The distance required to be covered by the skydiver to reach the final speed is found to be 378.22m.
The deceleration produced by the parachute is -0.0302m/s². The final and the initial velocity of the skydiver are 9m/s and 83m/s respectively.
Now, we know the equation of motion,
V² - U² = 2as
Where,
V and U are the final and the initial velocity,
a is the net acceleration,
s is the distance covered by the parachute.
Now, putting all the values,
(9)²-(83)² = 2(-0.0320)s
s = 378.22 m.
So, distance that should be travelled by the skydiver is 378.22m.
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in order to take quality notes, a student should have read the assigned chapter before listening to the lecture.
Answer:
it is true
Explanation:
after you size up the scene, the following are steps involved with performing a primary assessment for a child. place them in order in which they should occur.
The correct order of steps involved in performing a primary assessment for a child is check the patient for responsiveness, summon more advanced medical personnel, check for breathing and a pulse, and quickly scan for severe bleeding. The correct order is 2, 1, 4, and 3.
The first step in performing a primary assessment is to check the patient for responsiveness, if the child is responsive or not. This involves calling out their name, tapping their shoulder, or gently shaking them to see if they respond.
The next step is to summon more advanced medical personnel. If the child is not responsive or if you suspect a serious injury, it's important to call for more advanced medical personnel such as paramedics or emergency medical technicians (EMTs) as soon as possible.
Next, check for breathing and a pulse by checking if the child's airway, breathing, and pulse to make sure they're getting enough oxygen. If the child isn't breathing, begin cardiopulmonary resuscitation (CPR) immediately.
Then, quickly scan for severe bleeding. Look for any severe bleeding, such as from a major wound or a deep cut. If the child is bleeding severely, apply pressure to the wound to stop the bleeding.
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Your question seems incomplete, but I suppose the question was:
"After you size- up the scene, the following are steps involved with performing a primary assessment for a child. Place them in the order in which they should occur.
1. summon more advanced medical personnel
2. check the patient for responsiveness
3. quickly scan for severe bleeding
4. check for breathing and a pulse."
there is a single electron at a distance from the point charge. on which of the following quantities does the force on the electron depend?
The force acting on the electron is dependent upon the distance seen between positive charge and indeed the electron, the charges on the electron, and indeed the charge of something like the positive charge.
Why is there a positive charge?
A material that has more protons than electrons is said to have a positive charge. We are aware that electrons seem to be positively charged and protons become positively charged. Consequently, positively charged objects have more protons than electrons.
The positive charge is absent:
The positive charge on the protons and neutrons (red) results from an imbalance between protons and electrons, more particularly, when there are more protons than electrons. Protons can be added to an atom or other substance with both a neutral charge to produce a positive charge.
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The electric field points away from positive charges and toward negative charges. A distribution of charges creates an electric field that can be found by taking the vector sum of the fields created by individual point charges. Note that if a charge is placed in an electric field created by q', q will not significantly affect the electric field if it is small compared to q'.
Imagine an isolated positive point charge with a charge Q (many times larger than the charge on a single electron).
There is a single electron at a distance from the point charge. On which of the following quantities does the force on the electron depend?
Check all that apply.
A the distance between the positive charge and the electron
B the charge on the electron
C the mass of the electron
D the charge of the positive charge
E the mass of the positive charge
F the radius of the positive charge
G the radius of the electron
I got A, B, and D for this part of the problem and was correct. However,
For the same situation as in Part A, on which of the following quantities does the electric field at the electron's position depend?
Check all that apply.
A the distance between the positive charge and the electron
B the charge on the electron
C the mass of the electron
D the charge of the positive charge
E the mass of the positive charge
F the radius of the positive charge
G the radius of the electron
At the instant a traffic light turns green, a car that has been waiting at the intersection starts ahead with a constant acceleration of 2.00 m/s2 . At that moment a truck traveling with a constant velocity of 15.0 m/s overtakes and passes the car. (a) Calculate the time necessary for the car to reach the truck. (b) Calculate the distance beyond the traffic light that the car will pass the truck. (c) Determine the speed of the car when it passes the truck.
Answer:
Explanation:
(a) The time necessary for the car to reach the truck can be calculated using the equation for average velocity:
v_avg = v0 + at
where v0 is the initial velocity of the car (which is 0 m/s at the instant the light turns green), a is the acceleration of the car (2.00 m/s^2), and t is the time elapsed.
Since the truck is traveling with a constant velocity of 15.0 m/s, we can equate the average velocity of the car to the velocity of the truck:
v0 + at = 15.0 m/s
Solving for t, we get:
t = (15.0 m/s - v0) / a = 15.0 m/s / 2.00 m/s^2 = 7.50 s
(b) The distance beyond the traffic light that the car will pass the truck can be calculated using the equation for displacement:
d = v0t + 1/2at^2
Plugging in the values we found above, we get:
d = (0 m/s)(7.50 s) + 1/2(2.00 m/s^2)(7.50 s)^2 = 56.25 m
(c) The speed of the car when it passes the truck can be calculated using the equation for velocity:
v = v0 + at = 0 m/s + (2.00 m/s^2)(7.50 s) = 15.0 m/s
The water is flowing through a tapping pipe having diameter 400mm and 200mm at section 1 and 2 respectively. The discharge through the pipe is 0.06m³/sec. The section 1 is. 10m above datum line and section 2 is 6m above datum line. Find the intensity of pressure at section 2 to that if that of section 1 is 420 KN/m².
The intensity of pressure at section 2 is approximately 345.64 kN/m^2.
What is pressure?
Pressure is described as the force applied perpendicular to the surface of an object per unit area over which that force is distributed.
To determine the intensity of pressure at section 2, we need to use the equation of continuity and the Bernoulli equation:
we will substitute the values from the continuity equation into the Bernoulli equation which will give us :
P_1 + 1/2 * p * (Q_1 / A_1)^2 + p * g * h_1 = P_2 + 1/2 * p * (Q_2 / A_2)^2 + p * g * h_2
Substitute all the given values into the equation
Solving for P_2 = 420,000 N/m^2 + 47.06 KN/m^2 - 71.42 KN/m^2 = 345.64 KN/m^2
In conclusion, the intensity of pressure at section 2 is approximately 345.64 kN/m^2.
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All living things release energy from their food in a process called________, which happens inside their cells
Each of the following figures shows a person (not to scale) located on Earth at either 40°N or 40°S latitude. Rank the figures based on how much time the person spends in daylight during each 24-hour period, from most to least. To rank items as equivalent, overlap them.
Earth constantly moves. The Earth rotates around its axis once per day. The axis is the fictitious line passing through the middle of the planet, from the North to the South Poles.
What is Earths latitude?
It appears that the sun is moving across the sky as Earth spins, the sun is actually whirling. There are 24 hours in a day because it takes 24 hours to complete one rotation.
In other words, if the sun is visible in the morning beginning around 6:00 AM, the Earth will have spun around by 6:00 AM the following morning, and the sun will be seen in roughly the same location.
The Earth circles the sun and rotates on its axis. The Earth completes one full rotation of the sun in a little over 365 days.
Therefore, Earth constantly moves. The Earth rotates around its axis once per day. The axis is the fictitious line passing through the middle of the planet, from the North to the South Poles.
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Determine the current at point A in this circuit.
A) 2.6 A
B) 1.6 A
C) 1.8 A
D) 2.4 A
Answer:
2.6 A
Explanation:
Firstly here we need to find out the net resistance. 30Ω and 40Ω are grouped in parallel and to these 10Ω and 15Ω are in series. So we can find the net resistance as ,
[tex]\implies R_{net}=\dfrac{R_1R_2}{R_1+R_2} \\[/tex]
[tex]\implies R_{net}=\dfrac{30\times 40}{30+70}\Omega \\[/tex]
[tex]\implies R_{net}=\dfrac{120}{7}\Omega \\[/tex]
Again,
[tex]\implies R_{net}= R_1 + R_2+R_3 \\[/tex]
[tex]\implies R_{net}=\dfrac{120}{7}+10+15\Omega \\[/tex]
[tex]\implies R_{net}= \dfrac{120+105+70}{7}\Omega\\[/tex]
[tex]\implies R_{net}= \dfrac{295}{7}\Omega \approx 42\Omega \\[/tex]
Now use Ohm's law as ,
[tex]\implies V = iR \\[/tex]
[tex]\implies 110V = i\times 42\Omega\\[/tex]
[tex]\implies i =\dfrac{110}{42} A\\[/tex]
[tex]\implies \underline{\underline{ i = 2.6\ A }} \\[/tex]
and we are done!
. consider fictitious elements z and m. element z pulls on electrons a lot. element m does not pull on electrons much. determine which reaction will happen.
When considering fictitious elements Z and M, it is likely that element Z will have a higher ionization energy, meaning that more energy will be needed to remove an electron from it.
This means that when the two elements react, element Z will be more likely to gain electrons, while element M will be more likely to lose electrons. This means that element Z will be oxidized, while element M will be reduced.
Ionization energy, also known as ionization potential, is the amount of energy required to remove an electron from an atom or a molecule.
This process is referred to as ionization, and it involves the transfer of an electron from a neutral atom or molecule to form an ion with a positive charge.
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The balls are released from rest at a height of 5.0 m
at time t=0s
. Using these numbers and basic kinematics, you can determine the amount of time it takes for the balls to reach the ground.
Time taken by the ball to reach the ground is 1.0 second.
What is acceleration?Acceleration is rate of change of velocity with time. Due to having both direction and magnitude, it is a vector quantity. Si unit of acceleration is meter/second² (m/s²).
The initial height of the balls = 5.0 meter
Initial time = 0 second
The initial speed of the ball = 01 m/s
Acceleration due to gravity = 10.0m/s²
Hence, Time taken by the ball to reach the ground is = √(2 × 5.0/10.0) second
= 1.0 second.
Therefor it take 1.0 second to ball
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Help me please physics worksheet
Kinetic friction has a coefficient of 0.52 while static friction has a coefficient of 0.67.
What is friction?A force called friction prevents motion from occurring when two surfaces come into contact. Based on the characteristics of the two surfaces, their roughness, and the pressure used to press them together, it moves the objects in the opposite direction from the motion or planned motion.
How do you determine it?a. The formula friction = force of friction / normal force is used to calculate the coefficient of static friction.
The frictional force needed to move the chair is 165 N, and the normal force equals the chair's weight (25 kg * 9.8 m/s2 = 245 N).
The static friction coefficient is therefore equal to 165 N / 245 N = 0.67.
b. The formula friction = force of friction / normal force is used to determine the coefficient of kinetic friction.
The frictional force needed to maintain the chair's motion at a constant speed is 127 N, whereas the normal force remains 245 N.
Therefore, the kinetic friction coefficient is equal to 0.52 for 127 N/245 N.
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what is the potential energy of a charged ball?
Answer:
Explanation:
Potential energy means the energy of a material when it is not moving.
Ep= mgh
That's going to depend on the height of the ball above ground, and the amount of charge on the ball.
Sadly, you haven't shared either quantity with us.
If the stars Betelgeuse and Rigel each have the same luminosity, but the temperature of Betelgeuse is lower than Rigel, which star has the greater surface area? A. Betelgeuse B. Rigel C. They are the same size. D. There is insufficient information to answer this question.
Option A is Correct. Betelgeuse star has a larger surface area if Betelgeuse and Rigel both have the same brightness but Rigel's temperature is lower.
Rigel is usually always brighter than Orionis, despite the fact that the second-brightest star in each constellation is commonly referred to as "beta" (Betelgeuse). Therefore, red-glow objects are cooler than white-glow or blue-glow objects, despite what your water taps may claim.
Therefore, blue-white stars like Rigel and red stars like Betelgeuse have substantially lower surface temperatures. At 3,500 Kelvin, Betelgeuse's surface is warm. The brightness of Betelgeuse is extremely intense (40,000 times that of our Sun), but its surface is cold (less than 4000 K).
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Non skull bones of the axial skeleton
Answer:
humerus and all hand bones
Explanation:
not skull bones
in axial skel.
a new laptop was delivered to your home and left on the porch while you were at work. it is very cold outside, and you don't know how long it has been there. you unpack the laptop. you would like to know if it is working properly. which of the following is the best action to take?
The optimal course of action is to allow the laptop to warm up to room temperature before turning it on.
The room atmosphere and the outside temperature of the laptop are very different in terms of temperature.
When the user was at work and the laptop was discovered on the deck, it was delivered to his house. He is unable to recall how long it has been really chilly outside. The user opens his laptop and checks to see if everything is working correctly. Instead, turn on the machine at room temperature and let it preheat up.
When a computer is still in a frigid environment, it must warm up to room temperature for roughly 6 to 24 hours before being turned on. Otherwise, the heat the components produce might cause the laptop to become moist with water. The system's components might then be harmed by that water.
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1-m^3 volume of water is contained in a rigid container. Estimate the change in the volume of the water when a piston applies a pressure of 35 MPa.
The estimated change in water volume is -0.00056 [tex]m^3[/tex], which represents the volume reduction due to the applied pressure.
Where can I find volume?The formula for volume change is:
ΔV = -V * ΔP/B
where:
ΔV = volume change
V = initial volume
ΔP = pressure change
B = bulk modulus of water
After plugging in the values it looks like this:
ΔV = -1 [tex]m^3[/tex] * (35 x 10^6 Pa) / (2.2 x [tex]10^9[/tex] Pa)
= -0.00056[tex]m^3[/tex]
Therefore, the estimated change in volume of water is -0.00056 [tex]m^3[/tex], which represents the decrease in volume due to applied pressure.
How do you manually compute volume?The volume is determined by multiplying the dimensions of length, width, and height. Good news for cubes comes from the fact that each of these dimensions weighs exactly the same. As a result, we can add three to the length of any side. The formula that results is as follows: Front * Back Volume
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Amy, who has a mass of 68 kg, is riding her bicycle in the country. She is traveling at 11m / s when she begins to coast down a hill. She then coasts up another hill that is 15 m high and comes to a stop just as she reaches the top. How high was the first hill, in m? (Round your answer to one decimal place if necessary .)
The first hill was 6.17 meters high.
What is the velocity?Velocity is defined as the displacement of the object in a given amount of time and is referred to as velocity.
The work done on Amy and her bicycle by gravitational force can be calculated as follows:
W = mgh
where m is the mass of Amy and her bicycle, g is the acceleration due to gravity (9.8 m/s²), and h is the change in height.
When Amy is coasting down the first hill, her potential energy is converted to kinetic energy, so the work done by gravity is equal to the initial increase in kinetic energy:
W = (1/2)mv²
where v is the velocity. Setting these two equations equal to each other, we get:
mgh = (1/2)mv²
Solving for h, we get:
h = (1/2)v²/g
Plugging in the known values, we get:
h = (1/2)(11 m/s)²/9.8 m/s² = 6.17 m
Thus, the first hill was 6.17 m high.
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Which of the following is likely to happen when a glass of cold water is warmed to room temperature?Select the correct answer below:A. The water will absorb air as the solubility of its dissolved air increases.B. Small air bubbles will form as the solubility of its dissolved air decreases.C. The water will neither absorb nor release air because the solubility of its dissolved air does not change.D. We need more information to predict what will happen to the water.
Small air bubbles will form as the solubility of its dissolved air decreases when a glass of cold water is warmed to room temperature. Option B. is correct.
It's not as easy as it seems to pour water into a glass. Gases have been dissolved in them.
Furthermore, before we warm a glass of ice-cold water to room temperature, we must understand what we are doing. In essence, we are raising the water's temperature.
We now need to think about how rising temperatures will affect how soluble gases in the water.
By raising the temperature, we are supplying thermal energy in the form of heat to the gaseous molecules. The mobility and propensity to escape from the solution both increase as the thermal energy of the dissolved gaseous molecules rises. Because of this, the solubility of gases decreases as temperature rises.
As a result, when water is heated, gaseous molecules that have been dissolved begin to rise up from the water.
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Determine the number of cubic feet of air per minute required to cook a room having a sensible heat gain of 4500 btu per hour to a temperature of 78 F dry bulb, if the air enters the room at a temperature of 63 F and the outside temperature is 93F
It is given that, the heat gained is 4500 btu per hour. The temperature difference here is 30 F and the specific heat of air is 0.24 btu/lb°F. Then the cubic feet of air per minute is 138.8 CFM.
What is sensible heat transfer ?The sensible heat transfer in a system can be calculated using the equation below:
q = CFM × 1.08 ×ΔT
q = CFM x 0.075 lb/ft3 x 60 min/hour x 0.24 btu/lb°F x ∆T
where, 0.24 btu/lb°F is the specific heat of the dry air.
Given that q = 4500 btu/hour.
temperature difference = 93 F - 63 F.
Then 4500 btu/hr = CFM × 1.08 × 30 F
CFM of air = 4500 btu/hr /(1.08 × 30 F ) = 138.8 CFM.
There for the number of cubic feat of air per minute is 138.8.
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Find the distance traveled by a boy if he walks 3 km north and then turns and walks 1 km to the west.
Include both magnitude and direction.
Answer:
Explanation:
Distance = total length traveled = 3 + 1 = 4 km
Displacement² = 3² + 1² = 10
Displacement = √10 = 3.16
direction = tan⁻¹(3/-1) = 71.6⁰ north of west
a block hangs in equilibrium from a vertical spring. the equilibrium position sags by 7.00 cm when a second identical block is added. what is the oscillation frequency of the two-block system?
The oscillation frequency of the two-block system is 1.6 Hz.
What is equilibrium position?When a system is in equilibrium, neither its internal energy state nor its state of motion tend to change over time. A simple mechanical body is said to be in equilibrium if it neither experiences linear acceleration nor angular acceleration; unless it is disturbed by an external force, it will remain in that state indefinitely. If all of the forces acting on a single particle are vector summated to zero, equilibrium results. In addition to the states described above for the particle, a rigid body is said to be in equilibrium if the vector sum of all torques acting on it equals zero, keeping its state of rotational motion constant.
[tex]$$The oscillation frequency of the two-block is system is then found from Equation (3):$$\begin{aligned}f & =\frac{1}{2 \pi} \sqrt{\frac{k}{2 m}} \end{aligned}[/tex]
[tex]\begin{aligned}& =\frac{1}{2 \pi} \sqrt{\frac{196 \mathrm{~s}^{-2}}{2}} \\& =1.6 \mathrm{~Hz}\end{aligned}$$\\\\\text{where $2 m$ is the mass of the two blocks}[/tex]
Thus, the oscillation frequency of the two-block system is 1.6 Hz.
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A tank for scuba diving is designed to contain 50 standard cubic feet (SCF) of air when filled to a pressure of 3,000 pounds per square inch (gage) at an ambient temperature of 80 F. Calculate the interior volume of the tank and its length if the inside diameter is 6 in. A standard cubic foot of gas occupies one cubic foot at standard temperature and pressure (T=15C and p=101.3kPa absolute ).
The interior volume of the tank is 2.70 ft³ and its length is 34.0 inches.
What is pressure?
The force delivered perpendicularly to an object's surface per unit area across which this force is dispersed is known as pressure.
To calculate the interior volume of the tank, we can use the ideal gas law:
PV = nRT
At standard temperature and pressure (STP), one mole of an ideal gas occupies 22.4 liters (0.79 cubic feet). Therefore, 50 SCF of air is equivalent to:
n = (50 SCF) / (0.79 SCF/mol) = 63.3 mol
The temperature and pressure of the tank are not at STP, so we need to use the ideal gas law to calculate the volume. Rearranging the equation to solve for V, we get:
V = nRT/P
We can assume that the temperature remains constant at 80 F (which is equivalent to 26.7 C), and the pressure is 3000 psi. The gas constant R is 8.314 J/(mol K), or 10.73 psi·ft³/(mol K).
[tex]$\mathrm{V = \frac{ (63.3 mol) \times (10.73 psi\cdot ft^3 / (mol K)) \times (26.7 C + 273.15)}{(3000 psi)} }[/tex]
= 2.70 cubic feet
To find the length of the tank, we can use the formula for the volume of a cylinder:
[tex]\mathbf{V = \pi r^2h}[/tex]
where r is the radius (which is half the diameter) and h is the height (which is the length of the tank). We know that the diameter is 6 inches, so the radius is 3 inches (0.25 feet).
Substituting the known values into the equation, we get:
2.70 cubic feet = π (0.25 ft)² h
Solving for h, we get:
h = 34.0 inches
Therefore, the interior volume of the tank is 2.70 cubic feet and its length is 34.0 inches
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a long, straight metal rod has a radius of 4.60 cm and a charge per unit length of 27.4 nc/m. find the electric field at the following distances from the axis of the rod, where distances are measured perpendicular to the rod's axis
The distances from the axis of the rod (a long, straight metal rod has a radius of 4.60 cm and a charge per unit length of 27.4 nc/m.), where distances are measured perpendicular to the rod's axis
(a) 3.20 cm = 15.39 x 10³ N/c
(b) 2.0 cm = 2.43 x 10³ N/c
(c) 200 cm = 2.4 x 10² N/c
Given a long, infinite length and a constant charge per unit, the electric field is given by:
E = λ /2πε₀r
Where,
λ = wavelength (m)
ε₀ = 8.8542 x 10⁻¹²
r = radius (m)
Hence,
The distance are measured perpendicular to the rod's axis:
a. 3.20 cm
E = (27.4 x 10⁻⁹) / 2π (8.8542 x 10⁻¹²) (0.0320)
= 15.39 x 10³ N/c
b. 20 cm
E = (27.4 x 10⁻⁹) / 2π (8.8542 x 10⁻¹²) (0.2)
= 2.43 x 10³ N/c
c. 200 cm
E = (27.4 x 10⁻⁹) / 2π (8.8542 x 10⁻¹²) (2)
= 2.4 x 10² N/c
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Events in the environment trigger physiological arousal, which in turn, give the rise to the experience of emotion.
A 66 kg student traveling in a car with a constant velocity has a kinetic energy of 1.1 104 J. What is the speedometer reading of the car in km/h?
Answer:
The speedometer reading of the car in km/h is 100.1 km/h. This can be calculated by using the formula K = 0.5mv2, where K is the kinetic energy, m is the mass, and v is the velocity. Rearranging this equation to solve for v yields v = √(2K/m). In this case, m = 66 kg and K = 1.1 x 104 J, so v = √(2 x 1.1 x 104 J/ 66 kg) = 100.1 km/h.
Can someone please help me label this right
The tension at the top of the horizontal circle is T = m (v²/r - g ).
The tension at the bottom of the horizontal circle is m (v²/r + g ).
What is the tension at the bottom and top of the rope?
The tension at the bottom and top of he rope is calculated by applying the following formula as shown below;
The tension at the top of the horizontal circle is calculated as;
T = ma - mg
T = mv²/r - mg
T = m (v²/r - g )
where;
v is the speedr is the radius of the circleg is acceleration due to gravityThe tension at the bottom of the horizontal circle is calculated as;
T = ma + mg
T = mv²/r + mg
T = m (v²/r + g )
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The complete question is below:
Find the expression for the tension at the bottom and top of the circle
Which has more kinetic energy: a 0.0011-kg bullet traveling at 389 m/s or a 7.8 107-kg ocean liner traveling at 11 m/s (21 knots)?
Answer:
the ocean liner
Explanation:
KE = 1/2mv²
bullet: KE = 1/2(0.0011 kg)((389 m/s)² = 83.2 J
ship: KE = 1/2(7.8x10⁷ kg)(11 m/s)² = 4.7x10⁹ J
A ball is dropped, from
rest, from the top of a building. There are two motion sensors positioned
outside of two windows in the building to record the velocities of the ball
as it passes them. Sensor A is located above sensor B. Sensor A records
the ball’s velocity to be -15.5 m
s
and sensor B records the ball’s velocity to
be -17.2 m
s
. a) how far apart are the sensors?
b) how far from sensor a is the top of the building where the ball was released
c) if the time from when the ball passes sensor b until it hits the ground is 3.5s how tall is the building
Answer:
The sensors are approximately [tex]2.83\; {\rm m}[/tex] apart.
Sensor [tex]\texttt{a}[/tex] is approximately [tex]12.2\; {\rm m}[/tex] from the top of the building.
Height of the building is approximately [tex]135\; {\rm m}[/tex].
(Assumptions: air resistance on the ball is negligible; [tex]g = 9.81\; {\rm m\cdot s^{-2}}[/tex].)
Explanation:
Make use of the SUVAT equation [tex]x = (v^{2} - u^{2}) / (2\, a)[/tex], where [tex]x[/tex] represents displacement, [tex]v[/tex] and [tex]u[/tex] are the final and initial velocity, and [tex]a[/tex] is the acceleration.
In other words, as the velocity of the object changes from [tex]u\![/tex] to [tex]v\![/tex] at a rate of [tex]a[/tex], position of the object would have changed by [tex]x = (v^{2} - u^{2}) / (2\, a)[/tex].
a)When the ball is at sensor [tex]\texttt{a}[/tex], velocity of the ball was [tex]u = (-15.5)\; {\rm m\cdot s^{-1}}[/tex].
Shortly after, when the ball is at sensor [tex]\texttt{b}[/tex], velocity of the ball was [tex]v = (-17.2)\; {\rm m\cdot s^{-2}}[/tex].
Under the assumptions, [tex]a = (-g) = (-9.81)\; {\rm m\cdot s^{-2}}[/tex]. Apply the SUVAT equation [tex]x = (v^{2} - u^{2}) / (2\, a)[/tex] to find the change in the position of the ball between sensor [tex]\texttt{a}[/tex] ([tex]u = (-15.5)\; {\rm m\cdot s^{-1}}[/tex]) and [tex]\texttt{b}[/tex] ([tex]v = (-17.2)\; {\rm m\cdot s^{-2}}[/tex]):
[tex]\begin{aligned}x &= \frac{(-17.2)^{2} - (-15.5)^{2}}{2\, (-9.81)} \; {\rm m} \approx (-2.83)\; {\rm m}\end{aligned}[/tex].
Hence, the distance between sensor [tex]\texttt{a}[/tex] and [tex]\texttt{b}[/tex] is approximately [tex]2.83\; {\rm m}[/tex].
b)Since the ball was released from rest, the initial velocity of the ball would be [tex]u = 0\; {\rm m\cdot s^{-1}}[/tex].
Let [tex]v[/tex] denote the velocity of the ball at sensor [tex]\texttt{a}[/tex]: [tex]v = (-15.5)\; {\rm m\cdot s^{-1}}[/tex].
Apply the SUVAT equation [tex]x = (v^{2} - u^{2}) / (2\, a)[/tex] to find the change in the position of the ball between the top of the roof ([tex]u = 0\; {\rm m\cdot s^{-1}}[/tex]) and sensor [tex]\texttt{a}[/tex] ([tex]v = (-15.5)\; {\rm m\cdot s^{-1}}[/tex]):
[tex]\begin{aligned}x &= \frac{(-15.5)^{2} - (0)^{2}}{2\, (-9.81)} \; {\rm m} \approx (-12.2)\; {\rm m}\end{aligned}[/tex].
In other words, the distance between sensor [tex]\texttt{a}[/tex] and the top of the roof would be approximately [tex]12.2\; {\rm m}[/tex].
c)Another SUVAT equation, [tex]v = u + a\, t[/tex], gives the velocity of an object after accelerating for a duration of [tex]t[/tex] (at a rate of [tex]a[/tex], starting from an initial velocity of [tex]u[/tex].)
Make use of this SUVAT equation to find the velocity of the ball right before hitting the ground. Specifically, velocity of the ball was [tex]u = (-17.2)\; {\rm m\cdot s^{-1}}[/tex] at sensor [tex]\texttt{b}[/tex]. After accelerating at [tex]a = (-g) = (-9.81)\; {\rm m\cdot s^{-2}}[/tex] for [tex]t = 3.5\; {\rm s}[/tex], velocity of the ball would be:
[tex]\begin{aligned}v &= u + a\, t \\ &= (-17.2)\; {\rm m\cdot s^{-1}} + (-9.81)\, (3.5)\; {\rm m\cdot s^{-1}} \\ &= (-51.535)\; {\rm m\cdot s^{-1}} \end{aligned}[/tex].
Again, the velocity of the ball was [tex]u = 0\; {\rm m\cdot s^{-1}}[/tex] at the top of the building. Apply the SUVAT equation [tex]x = (v^{2} - u^{2}) / (2\, a)[/tex] to find the change in the position of the ball between the top of the building ([tex]u = 0\; {\rm m\cdot s^{-1}}[/tex]) and right before hitting the ground ([tex]v = (-51.535)\; {\rm m\cdot s^{-1}}[/tex]):
[tex]\begin{aligned}x &= \frac{(-51.535)^{2} - (0)^{2}}{2\, (-9.81)} \; {\rm m} \approx (-135)\; {\rm m}\end{aligned}[/tex].
the effective mass for electrons (in conduction band) is 5 times that of holes (in valence band), approximately how ef be from ev g
Holes are much lighter and more mobile than electrons in semiconductors. This difference in effective mass is a key factor in determining the electronic properties of materials such as B. Its conductivity, charge carrier mobility, and optical properties.
What do you understand by the the effective mass for electrons?The effective mass (meff) of an electron or hole in a solid is a measure of how a particle behaves as if it had a certain mass in a vacuum, even when interacting with crystal lattices and other particles in the solid. is. In general, the effective mass of an electron or hole depends on its energy and momentum.
In semiconductors with an energy bandgap, the valence band (VB) is separated from the conduction band (CB) by the bandgap energy (Eg). The energy of CB is higher than that of VB, the electrons in CB are free to move and conduct electricity, while the holes in VB are immobile and carry positive charge.
If the effective mass of electrons in CB is five times the effective mass of holes in VB, then the effective mass ratio can be expressed as
meff,electron / meff,hole = 5
Taking the reciprocals of both sides and rearranging them gives:
meff,hole / meff,electron = 1/5
This means that the effective mass of holes in VB is about one-fifth that of electrons in CB. In other words, holes are much lighter and more mobile than electrons in semiconductors. This difference in effective mass is a key factor in determining the electronic properties of materials such as: B. Its conductivity, charge carrier mobility, and optical properties.
To know more about the mass of electrons visit:
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The radius of the Earth is 6370 km. If a satellite orbits 150 km above the Earth's surface, what is the velocity of the orbit? The Earth's mass is 5.97 × 1024 kg. Give your answer in m-s¹, to three significant figures and do not include units.
Answer:
Approximately [tex]7.61 \times 10^{3}\; {\rm m\cdot s^{-1}}[/tex].
Explanation:
Add the radius of the Earth to the altitude of the satellite to find the radius of the orbit:
[tex]\begin{aligned}r &= (6370 + 150)\; {\rm km} \\ &= 6880\; {\rm km} \\ &= 6.88\times 10^{6}\; {\rm m}\end{aligned}[/tex].
Look up the gravitational constant:
[tex]G \approx 6.6743\times 10^{-11}\; {\rm m^{3}\, kg^{-1}\, s^{-2}[/tex].
Let [tex]m[/tex] denote the mass of the satellite. At an orbital velocity of [tex]v[/tex], the (centripetal) net force on the satellite would be:
[tex]\displaystyle (\text{net force}) = \frac{m\, v^{2}}{r}[/tex].
Let [tex]M[/tex] denote the mass of planet Earth. At a distance of [tex]r[/tex] from the center of the Earth, the gravitational attraction on the satellite would be:
[tex]\displaystyle (\text{gravitational attraction}) = \frac{G\, M\, m}{r^{2}}[/tex].
When the satellite is at the correct orbital velocity, the net force on the satellite would be equal to the gravitational attraction from the Earth. In other words:
[tex]\displaystyle (\text{net force}) = (\text{gravitational attraction})[/tex].
[tex]\displaystyle \frac{m\, v^{2}}{r} = \frac{G\, M\, m}{r^{2}}[/tex].
Rearrange the equation and solve for orbital velocity [tex]v[/tex]:
[tex]\begin{aligned}v^{2} &= \frac{G\, M}{r}\end{aligned}[/tex].
[tex]\begin{aligned}v &= \sqrt{\frac{G\, M}{r}} \\ &\approx \sqrt{\frac{(6.6743 \times 10^{-11})\, (5.97 \times 10^{24})}{6.88 \times 10^{6}}}\; {\rm m\cdot s^{-1}} \\ &\approx 7.61 \times 10^{3}\; {\rm m\cdot s^{-1}}\end{aligned}[/tex].