Answer:
19.6m/s
Explanation:
Given parameters:
Initial velocity = 0m/s
Time = 2s
Unknown:
Average velocity = ?
Solution:
We can use the final velocity of the ball before landing to determines its average velocity ;
Using;
v = u + gt
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
t is the time
v = 0 + 9.8 x 2 = 19.6m/s
Two floors in a building are separated by 4.1 m. People move between the two floors on a set of stairs. (a) Determine the change in potential energy of a 3.0 kg backpack carried up the stairs. (b) Determine the change in potential energy of a person with weight 650 N that descends the stairs.
Answer:
a) The change in potential energy of a 3.0 kilograms backpack carried up the stairs.
b) The change in potential energy of a persona with weight 650 newtons that descends the stairs is -2665 joules.
Explanation:
Let consider the bottom of the first floor in a building as the zero reference ([tex]z = 0\,m[/tex]). The change in potential energy experimented by a particle ([tex]\Delta U_{g}[/tex]), measured in joules, is:
[tex]\Delta U_{g} = m\cdot g\cdot (z_{f}-z_{o})[/tex] (1)
Where:
[tex]m[/tex] - Mass, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]z_{o}[/tex], [tex]z_{f}[/tex] - Initial and final height with respect to zero reference, measured in meters.
Please notice that [tex]m\cdot g[/tex] is the weight of the particle, measured in newtons.
a) If we know that [tex]m = 3\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]z_{o} = 0\,m[/tex] and [tex]z_{f} = 4.1\,m[/tex], then the change in potential energy is:
[tex]\Delta U_{g} = (3\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (4.1\,m-0\,m)[/tex]
[tex]\Delta U_{g} = 120.626\,J[/tex]
The change in potential energy of a 3.0 kilograms backpack carried up the stairs.
b) If we know that [tex]m\cdot g = 650\,N[/tex], [tex]z_{o} = 4.1\,m[/tex] and [tex]z_{f} = 0\,m[/tex], then the change in potential energy is:
[tex]\Delta U_{g} = (650\,N)\cdot (0\,m-4.1\,m)[/tex]
[tex]\Delta U_{g} = -2665\,J[/tex]
The change in potential energy of a persona with weight 650 newtons that descends the stairs is -2665 joules.
Water at the bottom of a falls has a velocity of 33 m/s after falling 25 m. What is the water speed at the top of the falls?
Answer:
Explanation:
Answer:
Speed of water at the top of fall = 5.40 m/s
Explanation:
We have equation of motion
Here final velocity, v = 26 m/s
a = acceleration due to gravity
displacement, s = 33 m
Substituting
Speed of water at the top of fall = 5.40 m/s
Three liters (3000 cm3) of oil is spilled onto a smooth lake. If the oil spreads out uniformly until it makes a circular oil slick just one molecule thick, with adjacent molecules just touching, estimate the diameter of the oil slick. Assume the oil molecules are round with a diameter of 2 x 10-10 m.
Answer:
4.38 km
Explanation:
Volume of oil slick, V = Area of oil slick, A × thickness of 1 molecule, d'
Since the oil slick spreads out in a circular area, it has the area of a circle.
So, V = πd²/4 × d'
d² = 4V/πd'
d = 2√(V/πd') where d = diameter of oil slick.
Since V = 3000 cm³ = 3000 × 10⁻⁶ m³ = 3 × 10⁻³ m³ and d' = 2 × 10⁻¹⁰ m
So, d = 2√(3 × 10⁻³ m³/(π × 2 × 10⁻¹⁰ m))
= 2√(3 × 10⁻³ m³/(6.283 × 10⁻¹⁰ m))
= 2√(0.477 × 10⁷ m²) = 2√(4.775 × 10⁶ m²)
= 2 × 2.19 × 10³ m
= 4.38 × 10³ m
= 4.38 km
If an object was observed to orbit the Sun once every half of a year, what would be this object's average distance from the Sun according to Kepler's third law?
A. 0.63 au
B. 0.25 au
C. 0.79 au
D. 0.71 au
Your bedroom has a rectangular shape and you want to measure its size. You use a tape that is precise to 0.001 mm and find that the shortest wall in the room is 3.547 mm long. The tape, however, is too short to measure the length of the second wall, so you use a second tape, which is longer but only precise to 0.01 mm. You measure the second wall to be 4.79. Which of the following numbers is the most precise estimate that you can obtain from your measurements for the area of your bedroom?
a. 30 m^2
b. 31.4 m^2
c. 31.37 m^2
d. 31.371 m^2
This question is in two parts. This is not the correct multiple choice options for this part a.
The second part had the option
b)If your bedroom has a circular shape, and its diameter measured 6.32 , which of the following numbers would be the most precise value for its area?
a)30 m^2
b) 31.4 m^2
c)31.37 m^2
d)31.371 m^2
Answer:
A. 17.0 m²
B. 31.4 m²
Explanation:
The formula for the calculation of the area of a rectangle is given as
Area = length x width
The length = 3.547 m
The width = 4.79 m
Then area = 3.547 x 4.79
= 16.990m²
When approximated = 17.0m²
This is the most precise measurement for the area of the bedroom.
B.
We solve b using this formula
Area = pi(diameter/2)^2
= 3.14(6.32/2)²
= 3.14 x 9.9856
= 31.4 m²
A 5 kg ball was hit with 1523 J of energy how fast is it going?
a. 304.6 m/s
ь. 39 m/s
C 609.2 m/s
d. 1.218.4 m/s
Answer:
the answer is a 304.6m/s
Explanation:
1,523 / 5 equals 304.6
Who invented gravity
Answer: joe
Explanation:
Answer:
Sir Isaac Newton
Explanation:
Sir Isaac Newton was an English mathematician and mathematician and physicist who lived from 1642-1727. The legend is that Newton discovered Gravity when he saw a falling apple while thinking about the forces of nature.
Allen and Jason are chucking a speaker around. On one particular throw, Allen throws the speaker, which is playing a pure tone of frequency f, at a speed of 10 m/s directly towards Jason, but his aim is a bit off. As a result, Jason runs forward towards the speaker at a speed of 6 m/s before catching it. Then, the frequency that Jason hears while running can be written as (m/n)f Hz, where m and n are relatively prime positive integers. Compute m n.
Answer:
Explanation:
We shall apply Doppler's effect of sound .
speaker is the source , Jason is the observer . Source is moving at 10 m /s , observer is moving at 6 m/s .
apparent frequency = [tex]f_o\times\frac{V+v_o}{ V-v_s}[/tex]
V is velocity of sound , v₀ is velocity of observer and v_s is velocity of source and f_o is real frequency of source .
Here V = 340 m/s , v₀ is 6 m/s , v_s is 10 m/s . f_o = f
apparent frequency = [tex]f\times \frac{340+6}{340-10}[/tex]
= [tex]f\times \frac{346}{330}[/tex]
So m = 346 , n = 330 .
At a certain elevation, the pilot of a balloon has a mass of 120 lb and a weight of 119 lbf. What is the local acceleration of gravity, in ft/s2, at that elevation
Answer:
31.905 ft/s²
Explanation:
Given that
Mass of the pilot, m = 120 lb
Weight of the pilot, w = 119 lbf
Acceleration due to gravity, g = 32.05 ft/s²
Local acceleration of gravity of found by using the relation
Weight in lbf = Mass in lb * (local acceleration/32.174 lbft/s²)
119 = 120 * a/32. 174
119 * 32.174 = 120a
a = 3828.706 / 120
a = 31.905 ft/s²
Therefore, the local acceleration due to gravity at that elevation is 31.905 ft/s²
why is red light used in photographic dark rooms
Photographic paper reacts to light to produce the image taken by a camera and stored on film. Darkrooms used red lighting to allow photographers to control light carefully, so that light-sensitive photographic paper would not become overexposed and ruin the pictures during the developing process.
Answer:
Photographic paper reacts to light to produce the image taken by a camera and stored on film.
Explanation:
Darkrooms used red lighting to allow photographers to control light carefully so that light-sensitive photographic paper would not become overexposed and ruin the pictures during the developing process.
the force that makes objects keep traveling is ____.
a.gravity
b.inertia
c.attraction
d.energy
Answer:
D-Energy
Explanation:
Answer: b. inertia
According to Newton's First Law of Motion, if an object is at rest, then it stays at rest as long as no external forces are applied to get the object moving. If an object is in motion, then it stays in motion (again as long as no external forces are applied to say otherwise). This is known as inertia.
For example, if you were to launch a baseball into deep space (far from any planet), then the ball will travel in a straight line at a constant speed until it either hits another object to have it slow down, or another planet's gravity starts to pull on the ball.
Calculate the momentum of a 48.5 kg passenger seated on a train that is stopped.
Answer:
0kgm/s
Explanation:
Given parameters:
Mass of the passenger = 48.5kg
Unknown:
Momentum = ?
Solution:
The momentum of a body is the quantity of motion a body possesses. A body not in motion has no momentum.
Mathematically;
Momentum = mass x velocity
So;
Since the train is stopped, velocity = 0m/s
Momentum = 48.5 x 0 = 0kgm/s
Interesting fact about the rib
Answer:
YOU CAN SNEEZE YOUR WAY TO A RIB FRACTURE.
Explanation:
what is phase voltage of star connected three phase system in balanced loa is 240 the line voltage
Answer:
Explanation: the Star Connection, the similar ends (either start or finish) of the three windings are connected to a common point called star or neutral point. The three-line conductors run from the remaining three free terminals called line conductor
How much force is needed to move a 12 kg mass 10 m/s?? FEMA
Answer:
F=ma
=12×10
120 N.........
Answer:
F = 120 N [Newtons]
Explanation:
F = 120N
If the speed is 10m/s² [an acceleration], and the mass is 12 kg [kilograms].
F [Force] = ma [mass × acceleration].
F = 10 × 12 = 120.
It cannot be a velocity because time is not given.
Momentum would be the velocity times mass. p = mv.
A piece of putty and a tennis ball with the same mass are thrown against a wall with the same velocity. Which object experiences a greater force from the wall or are the forces equal
Answer:
Explanation:
Firstly, we have to define momentum.
Momentum is define as the product of mass and velocity.
That is P = mass×velocity
Also considering the third law of motion which states that: For every action, there is equal and opposite reaction.
Moreso, considering the 2nd law of motion which states that the rate of change in the momentum of a body is equal to the applied force and takes place in the direction of the applied force.
Now, applying P = mass×velocity
They both have same mass and velocity definitely, they will both experience same momentum.
Also from the question, the both share same velocity hence, the will both hit the wall with same velocity meaning the will both feel the same impact from the wall as well. Hence the third law of motion proves this right.
If two connected points objects pass through the same set of three points, the shapes created by each will be identical, regardless of the order in which each object was plotted. True
Answer:
This is false
Explanation:
This is why the answer to this question is false. If these types of objects (2 points connected) should pass through same sets of 3 points, irrespective of the order that each object was plotted, we will not get identical shapes created.
The shape that is going to be created will be dependent on the pattern/order that was involved in the plotting. If it was identical, then we will have identical shapes. But if the order during plotting is different then we will have different shapes created.
Thank you!
2. A gas with a constant pressure of 270 kPa does 36,000 J of work as it expands.
What was the change in volume of the gas?
a) 0.13 meters cubed
b) 0.24 meters cubed
c) 0.33 meters cubed
d) 0.46 meters cubed
You yell into a canyon. You hear the echo in 3 seconds. How long did the sound of your voice travel before bouncing off a cliff?
Answer:
The sound travelled 516 meters before bouncing off a cliff.
Explanation:
The sound is an example of mechanical wave, which means that it needs a medium to propagate itself at constant speed. The time needed to hear the echo is equal to twice the height of the canyon divided by the velocity of sound. In addition, the speed of sound through the air at a temperature of 20 ºC is approximately 344 meters per second. Then, the height of the canyon can be derived from the following kinematic formula:
[tex]2\cdot h = v\cdot t[/tex] (1)
Where:
[tex]h[/tex] - Height, measured in meters.
[tex]v[/tex] - Velocity of sound, measured in meters per second.
[tex]t[/tex] - Time, measured in seconds.
If we know that [tex]v = 344\,\frac{m}{s}[/tex] and [tex]t = 3\,s[/tex], then the height of the canyon is:
[tex]h = \frac{v\cdot t}{2}[/tex]
[tex]h = \frac{\left(344\,\frac{m}{s} \right)\cdot (3\,s)}{2}[/tex]
[tex]h = 516\,m[/tex]
The sound travelled 516 meters before bouncing off a cliff.
An energy source forces a constant current of 2A to flow through a light bulbfilament for twenty seconds. If 4.6 kJ is given off in the form of light and heatenergy, calculate the voltage drop across the bulb.
Answer:
The voltage drop across the bulb is 115 V
Explanation:
The voltage drop equation is given by:
[tex]V=\frac{\Delta W}{\Delta q}[/tex]
Where:
ΔW is the total work done (4.6kJ)
Δq is the total charge
We need to use the definition of electric current to find Δq
[tex]I=\frac{\Delta q}{\Delta t}[/tex]
Where:
I is the current (2 A)
Δt is the time (20 s)
[tex]2=\frac{\Delta q}{20}[/tex]
[tex]q=40 C[/tex]
Then, we can put this value of charge in the voltage equation.
[tex]V=\frac{4600}{40}=115 V[/tex]
Therefore, the voltage drop across the bulb is 115 V.
I hope it helps you!
Sarah is a forensic what is her job to do
Answer:
She takes pictures and analyzes DNA samples
Convert 41.3 kilocalories into joules.
Answer:172799.2
Explanation:
You are given two identical neutral metal spheres A and B mounted on fixed insulating supports, as well as a thin conducting wire and a glass rod that you can rub with silk. You can attach the wire between the spheres or between a sphere and ground. You cannot touch the rod to a sphere or between a sphere and the ground. You cannot touch the rod to a sphere. How can you give the spheres charges of:
a. equal magnitude and the same sign?
b. equal magnitude and opposite signs?
Answer:
a) we bring the rod closer to one of the spheres connected to Earth,
we disconnect the ground cable and move the rod away and join the two spheres with the wire
b) we connect a sphere to ground, bring the rod closer
we disconnect the ground cable
Now we bring the rod closer to the other isolated sphere
Explanation:
In this interesting exercise we will use that electric charges are of two types positive and negative, where charges of the same sign repel and of opposite sign attract.
In metals the charges are mobile and can be displaced, we will conspire the earth as a receptor of charges and the glass rod does not have mobile charges, but it does have charges created by friction with silk.
With these concepts let's analyze the requested situations
a) How to create charge of equal magnitude and same sign in the spheres.
To create this situation we bring the rod closer to one of the spheres connected to Earth with the wire, in this case the charge induced by the sphere stops to the ground, then we disconnect the ground cable and move the rod away, therefore the sphere that with a charge of equal magnitude of the rod but of opposite sign.
Now we join the two spheres with the wire and the charge is distributed between the two, we remove the wire and each sphere with a charge equal to the mistad of the cheek and of the opposite sign.
Therefore the two spheres have a charge of equal magnitude and sign.
b) how to create charge of equal magnitude and opposite signs.
For this case we connect a sphere to ground with the wire, we bring the rod closer and an induced charge is created on the sphere of equal magnitude to the rod charge and of opposite sign, an equal charge and of the same sign as the rod passes to ground through the wire, disconnect the wire and remove the rod. The sphere with a charge equal to that of the rod and with the opposite sign.
Now we bring the rod closer to the other isolated sphere, an induced charge of opposite sign to the rod and of the same magnitude is created,
in this case we keep the rod in this position and we have two charges of equal magnitude, but without opposite in each sphere
The 88-lb force P is applied to the 210-lb crate, which is stationary before the force is applied. Determine the magnitude and direction of the friction force F exerted by the horizontal surface on the crate. The friction force is positive if to the right, negative if to the left. Assume 0.47, 0.35.
Answer:
[tex]F=-88Ib[/tex]
Explanation:
From the question we are told that:
Force P=88Ib
Mass of crate M_c=210Ib
Generally the equation for Frictional force F is mathematically given by
[tex]Friction\ force (f) = friction\ coefficient\ (u) * Normal\ reaction (N)[/tex]
[tex]F=u*N[/tex]
with [tex]\mu =0.47[/tex]
[tex]F=98.7Ib[/tex]
Therefore since Static Friction supersedes applied force body remains at rest.
Frictional force =88Ib (negative)
[tex]F=-88Ib[/tex]
If it took you 5 seconds to move a rock 15 meters using a force of 150 Newtons, how much power did you need to use?
500 joules/sec
45 joules/sec
4,500 joules
450 joules/sec
Answer:
Given that:
Time taken = 5 seconds
Distance = 15 meters
Force = 150 Newtons
Power = ?
Recall that power is the rate of work done per unit time
i.e Power = work / time
(since work is a product of force and distance, then
power = (force x distance)/ time
Power = (150 Newtons x 15 m) / 5 s
Power = 2250 / 5
Power = 450 joules per second
Answer:
450 joules/sec
Explanation:
150 x 15 = 2,250
2,250 / 5 = 450
= 450 joules/sec
What happens to your kinectic energy when your gravitational potential energy decreases?
Answer:
As r decreases, we lose gravitational potential energy - in other words, U G U_G UGU, start subscript, G, end subscript becomes more negative. Because energy is conserved, the velocity must increase, resulting in an increase in kinetic energy.
Explanation:
Balance this chemical equation.
Hlint: Balance Al last and then use a multiple of 2 and 3.
Al + HCl —> AICI3 + H2
Answer:
2Al + 6HCl _> 2AlCl3 + 3H2
Answer:
please refer to the above attachment.
A catcher in a baseball game stops a pitched ball that was originally moving at 44 m/s over a distance of 12.5 cm. the mass of the ball is 0.15 kg. what is the average force that the glove imparts to the ball during the catch
Answer:
Force = -1161.6 Newton
Explanation:
Given the following data;
Initial velocity, u = 44m/s
Distance ,s = 12.5cm to m = 12.5/100 = 0.125m
Mass = 0.15kg
To find the acceleration;
We would use the third equation of motion;
V ² = U² + 2as
0² = 44² + 2*a*0.125
0 = 1936 + 0.25a
0.25a = -1936
a = -1936/0.25
Acceleration, a = -7744m/s2
Force = mass * acceleration
Substituting into the equation, we have;
Force = 0.15 * (-7744)
Force = -1161.6 Newton
The value of its force is negative because the glove decreases the velocity of the ball.
Determine the magnitude of the resultant force FR=F1+F2FR=F1+F2. Assume that F1F1F_1 = 235 lblb and F2F2F_2 = 350 lb
Answer:
585lb
Explanation:
Given the formula for calculating the magnitude of the resultant force as;
[tex]F_R = F_1 + F_2[/tex]
Given
[tex]F_1 = 235 lb \ and \ F_2 = 350 lb\\F_R = 235lb + 350lb\\F_R = 585lb\\[/tex]
Hence the magnitude of the resultant force is 585lb
A golfer hits her tee-shot due north towards the fairway. Her shot has an initial velocity of 60 m/s. A 15 m/s wind is blowing in a northwesterly direction (45 degrees west of North). Considering the initial velocity of the ball and the velocity of wind, what will be the resultant velocity (m/s) and the resultant direction of the golf ball assuming no other forces are acting on the ball
Answer:
[tex]c=71.4m/s[/tex]
[tex]\theta=8.54\textdegree[/tex]
Explanation:
From the question we are told that
Initial velocity of 60 m/s
Wind speed [tex]V_w= 15 m/s \angle 45 \textdegree[/tex]
Generally Resolving vector mathematically
[tex]sin(45\textdegree)15=10.6\\cos(45\textdegree)15=10.6[/tex]
Generally the equation Pythagoras theorem is given mathematically by
[tex]c^2=a^2+b^2[/tex]
[tex]c^2=10.6^2 +(10.6+60)^2[/tex]
[tex]c=\sqrt{10.6^2 +(10.6+60)^2}[/tex]
Therefore Resultant velocity (m/s)
[tex]c=71.4m/s[/tex]
b)Resultant direction
Generally the equation for solving Resultant direction
[tex]\theta=tan^-1(\frac{y}{x})[/tex]
Therefore
[tex]\theta=tan^-1(\frac{10.6}{70.6})[/tex]
[tex]\theta=8.54\textdegree[/tex]