Answer:
Explanation:
For discharge of capacitor in RC circuit , the relation is as follows
[tex]V=V_0e^\frac{-t}{\lambda}[/tex]
V is voltage across the capacitor , V₀ is maximum voltage across capacitor , λ is time constant and t is the time after which the voltage is recorded. During discharge this will also be voltage across resistance .
Taking log on both sides
lnV = lnV₀ - [tex]\frac{t}{\lambda}[/tex]
Given equation
[lnV] = - .027 t + 2.5
Comparing these equation
[tex]\frac{1}{\lambda} = .027[/tex]
λ = 37 s
time constant = 37 sec.
The surface tension of water was determined in a laboratory by using the drop weight method. 100 drops were released from a burette the inner diameter of whose opening is 1.8 mm
Answer:
0.06563 N/m
The percentage difference between the calculated and tabulated value of water surface tension is 9.78%
Explanation:
Solution:-
- Surface tension is the ability of any fluid to resist any external force due to cohesive nature of the fluid molecules.
- Surface tension ( γ ) is defined as the force imparted per unit length on the fluid.
γ = F / L
Where,
F: Force
L: The length over which force is felt
- The mass ( M = 3.78g ) of ( n = 100 ) water droplets are carefully burette. We need to determine the mass of a single droplet as follows:
m = M / n
m = 3.78 / 100
m = 0.0378 g
- Assuming the distance over which the drop falls is negligible and resistive forces are negligible. Then the only force acting on the droplet is due to gravity ( Weight of the droplet ):
F = m*g
F = 0.0378*9.81*10^-3
F = 0.000370818 N
- The length over which the force is felt can be modeled into a circular patch with diameter ( d ) = equal to the diameter ( d ) of the single water drop. The length ( L ) is defined as the circumference of the patch:
L = π*d
L = π*( 0.0018 )
L = 0.00565 m
- The surface tension would be:
γ = F / L
γ = 0.000370818 / 0.00565
γ = 0.06563 N / m
- The given value of water's surface tension is given as follows:
γa = 0.07275 N/m
- To compare the two values we will determine the percentage difference between the value evaluated and tabulated value as follows:
% [tex]diff = \frac{0.07275- 0.06563}{0.07275} * 100 \\\\diff = 9.78 \\\\[/tex]
- The percentage difference ( 9.78% ) between the two values is within practical limits of 10%. Hence, the calculated can be accepted.
How did astronomers precisely determine the length of an Astronomical Unit in the 1960s?
Answer:
Use of telemetry and radar astronomy
Explanation:
An astronomical Unit (AU) is a unit of measuring distances in outer space, which is based on the approximate distance between the earth and the Sun.
After several years of trying to approximate the distance between the Sun and the Earth using several methods based on geometry and some other calculations, advancements in technology made available the presence of special motoring equipment, which can be placed in outer space to remotely monitor and measure the position of the sun.
The use of direct radar measurements to the sun (radar astronomy) have also made the determination of the AU more accurate.
A standard radar pulse of known speed is sent to the Sun, and the time with which it takes to return is measured, once this is recorded, the distance between the Earth and the Sun can be calculated using
distance = speed X time.
However, most of these means have to be corrected for parallax errors
HELP 25 POINTS MULTIPLE CHOICE
The energy due to the motion of an object is....
A)non mechanical B) potential C) thermal D) kinetic
Answer:
D) Kinetic.
Explanation:
Kinetic energy is energy in motion.
Answer: D
Explanation: kinetic is also called energy of motion , it is defined at the work needed to accelerate a body of a given mass from rest to its stated velocity.
A 1 meter wide door is initially open at an angle of 30o as shown (top view). You push with 20 N force in the middle of the door as shown and the door rotates around the hinge on the left. The door has a rotational inertia =3.0 kg m2. The angular acceleration of the door will be:
Answer:
angular acceleration = 1.67 rad/s²
Explanation:
given data
door wide = 1 m
initially ope angle = 30°
push force = 20 N
rotational inertia = 3.0 kg m²
solution
we apply force at middle so length will be here r1 = [tex]\frac{1}{2}[/tex] = 0.5 m
and
now we get here torque that is express as
torque τ = Force × r1 × sin30 ......................1
put her value and we get
torque τ = 20 × 0.5 × sin30
torque τ = 5 Nm
and we know
torque = rotational inertia × angular acceleration .......................2
put her value and we get angular acceleration
angular acceleration = [tex]\frac{5}{3}[/tex]
angular acceleration = 1.67 rad/s²
Where is the density of the material greater, at point B or point C?
Explain why.
Answer: The density is greater at point C
Explanation: At that point
The convention current slowly cools off
Your latest invention is a car alarm that produces sound at a particularly annoying frequency of 3585 Hz. To do this, the car-alarm circuitry must produce an alternating electric current of the same frequency. That's why your design includes an inductor and a capacitor in series. The maximum voltage across the capacitor is to be 12.0 V (the same voltage as the car battery). To produce a sufficiently loud sound, the capacitor must store 0.0163 J of energy. What values of capacitance and inductance should you choose for your car-alarm circuit?
Answer:
Explanation:
Energy stored in a capacitor = 1/2 C V² where , C is capacitance and V is potential of capacitor.
Putting the values
.5 x C x 12² = .0163
C = 226.4 x 10⁻⁶ F .
Frequency of L-C circuit = [tex]\frac{1}{2\pi}\sqrt{\frac{1}{LC} }[/tex]
where L is inductance of inductor and C is capacitance of capacitor.
putting the values
3585 = [tex]\frac{1}{2\pi}\sqrt{\frac{1}{L\times226.4\times10^{-6}} }[/tex]
506.87 x 10⁶ = [tex]\frac{1}{L\times226.4\times10^{-6}}[/tex]
[tex]L = \frac{1}{114755.37}[/tex]
= 8.7 x 10⁻⁶ H.
How many meters are there in 6.50 ly ? Express your answer using three significant figures.
Answer:
6.5 ly is equal to 6.15 x 10¹⁶ m
Explanation:
Light year is the unit of length. It can easily be calculated by multiplying the speed of light in vacuum withe no. of seconds in an year. Let us calculate the value of 1 light year in meters.
1 Light Year = (Speed of Light)(Seconds in 1 Year)
1 Light Year = (3 x 10⁸ m/s)(1 year)(365 days/year)(24 h/day)(3600 s/h)
1 Light Year = 9.46 x 10¹⁵ m
Hence, to get the value of 6.5 Light years, in meters, we will multiply both sides by 6.5.
6.5 Light Years = (6.5)(9.46 x 10¹⁵ m)
6.5 Light Years = 6.15 x 10¹⁶ m
OR
6.5 ly = 6.15 x 10¹⁶ m
Therefore, there are 6.15 x 10¹⁶ m in 6.5 ly
what unit is used to measure the downwards force of weight?
Answer: Newton denoted using N
Examples: 25 N
Please rate 5 stars and vote as brainliest:)
(^o^)(^o^)(^o^)(^o^)(^o^)(^o^)(^o^)(^o^)(^o^)(^o^)
Which of the following are vectors?
Check all that apply.
O A. energy
B. displacement
O C. force
D. mass
E. momentum
F. speed
G. time
O H. velocity
Answer:
Displacement, force, momentum, and velocity are all vectors
Explanation:
Vectors are quantities that show direction; which all of the above do. The rest of the terms are scalar quantities
a) Fill in the blanks in the following paragraph to correctly describe the nucleus of an atom.
_______ and _________ are the two types of nucleons that make up a nucleus. The __________ force exists between _________ in the nucleus because of their charge. Because it is repulsive, this force tends to make a nucleus __________. However, the __________ force acts between protons, between neutrons, and between protons and neutrons. This force helps to make a nucleus __________, because it is always attractive.
Answer:
Protons and Neutrons are the two types of nucleons that make up a nucleus. The electrostatic force exists between protons in the nucleus because of their charge. Because it is repulsive, this force tends to make a nucleus unstable. However, the strong nuclear force acts between protons, between neutrons, and between protons and neutrons. This force helps to make a nucleus stable, because it is always attractive.
Explanation:
The nucleus of an atom contains two types of particles, protons and neutrons. Proton has a positive charge, while neutron has no charge. The protons have a repulsive electrostatic force between each other, due to like charges. Due to this repulsive force protons tend to scatter away making the nucleus unstable. In order to overcome this, a force inside the nucleus binds these protons and neutrons together. This attractive force is called strong nuclear force. This force acts on very short ranges.
An atom is made up of nucleus and electrons orbitting the nucleus. The correct words are proton, neutron, electrostatic force, protons, unstable, nuclear, stable respectively.
Nucleus:
It is composed of Protons and Neutrons. Protons are potsitively charged , hence repulse each other which makes the nucleus unstable.
Nucleons held together by Strong nucleur force because it is the strongest force of universe.
To know more about Strong nucleur force
https://brainly.com/question/11254569
define centre of mass
Answer:
a point representing the mean position of the matter in a body or system.
Explanation:
Two bicycle tires are set rolling with the same initial speed of 3.1 m/s m/s along a long, straight road, and the distance each travels before its speed is reduced by half is measured. One tire is inflated to a pressure of 40 psi psi and goes a distance of 19.0 m m ; the other is at 105 psi psi and goes a distance of 93.0 m m . Assume that the net horizontal force is due to rolling friction only and take the free-fall acceleration to be g gg = 9.8 m/ s 2 m/s2 . Part A What is the coefficient of rolling friction μ r μrmu_r for the tire under low pressure?
Answer:
Explanation:
From the formula
v² = u² + 2 a s , v is final velocity , u is initial velocity , a is acceleration and s is distance travelled .
u² / 4 = u² + 2 a x 19
- 3/4 u² = 2 a x 19
- (3 / 4) x 3.1² = 2 x 19 x a
a = - .18967 m /s²
deceleration due to friction = μg where g is acceleration due to gravity and μ is coefficient of friction .
a = μg
μ = a / g
= .18967 / 9.8
= .019 .
A periodic wave travels from one medium to another. Which pair of variables are likely to change in the process? A. velocity and wavelength B. velocity and frequency C. frequency and wavelength D. frequency and phase E. wavelength and phase
Answer:
A. velocity and wavelength
Explanation:
When a wave travels from one medium to another it undergoes refraction which results to the change in direction.
Refraction of a wave is one of the property of waves that occurs when a wave changes direction when it passes from one medium to another. This occurs as a result of bending of the wave which occurs since the mediums involved are of different density and refractive index.
Apart from the change in direction, refraction is accompanied by the change in wavelength of a wave and thus a change in speed.
Answer:
A. velocity and wavelength
Explanation:
Infer the effect of deforestation on the carrying capacity of the Amazon rainforest.
Answer:
More than 20% of the amazon has been destroyed, affects biodiversity.
Explanation:
The biggest issues that the amazon is facing is the deforestation and it involves the clearing of land areas for logging, farming, and other land-use changes. Effects that are seen are droughts, floods, destruction of habitats of flora and fauna along with the valuable services of the ecosystem. This leads to a decrease in the carrying capacity of the species and the decline of the essential resources that are necessary to survive.Sone one explain equilibrium to me what is it
Answer:
In econ: When supply and Demand are equal
Explanation:
Equilibrium is when something evens out
A soccer ball player bounces the ball off her head, changing the velocity of the ball. She changes the x-component of the velocity of the ball from vix = 7.9 m/s to vfx = 5.9 m/s and the y-component from viy = −3.4 m/s to vfy = 4.5 m/s.
If the ball has a mass of 0.40 kg and is in contact with the player's head for 7.1 ms, determine the direction of the impulse (in degrees counterclockwise from the +x-axis) delivered to the ball.
Answer:
Explanation:
change in momentum along x axis = mass ( final velocity - initial velocity )
= .4 ( 5.9 - 7.9 )
= - .8 kg m /s
change in momentum along y axis = mass ( final velocity - initial velocity )
= .4 ( 4.5 + 3.4 )
= 3.16 kg m/s
Force along x axis be Fx
Fx . t = change in momentum along x axis = - .8
Fy . t = change in momentum along y axis = 3.16
Direction of impulse =
Tanθ = Fy . t / Fx . t , θ is angle from x axis along anticlockwise direction.
= 3.16 / - 0 .8 .
= - 3.95
θ = 165.8 degree from positive x - axis. anticlockwise.
a student constructed a simple electric circuit where two light bulbs were connected in parallel. The circuit power source was a 6.0-V cell. One of the light bulbs had a resistance of 25 ohms, and the other had a resistance of 50 ohms. What was the combined resistance of the light bulbs in the circuit?
a) 75ohms
b) 42ohms
c) 25ohms
d) 17ohms
Answer:
RT = 17 ohms
Explanation:
For two parallel resistances in a circuit the combined resistance is given by:
[tex]\frac{1}{R_T}=\frac{1}{R_1}+\frac{1}{R_2}\\\\\frac{1}{R_T}=\frac{R_2+R_1}{R_1R_2}\\\\R_T=\frac{R_1R_2}{R_1+R_2}[/tex]
R1 = 25 ohms
R2 = 50 ohms
You replace the values of R1 and R2 in the formula for RT:
[tex]R_T=\frac{(25)(50)}{25+50}ohms=16.66\ ohms \approx 17\ ohms[/tex]
hence, the combined resitances is 17 ohms
List of priceless your bodies from largest to smallest in terms of their distance from earth
Answer:
hi
Explanation:
hi
The curve (The Load elongation) for rabbit tendon tested to failure in tension is given in the figure above. Please describe the behavior of the tendon in each interval.
Answer:
Explanation:
Elasticity is the tendency of a material to regain its original shape and size after being deformed by an external force. Hooke's law of elasticity state that; provided the elastic limit of a material is not exceeded, the extension is proportional to the force applied.
The given graph shows the elastic property of the rabbit's tendon when a force (load) is applied.
At point 1 on the graph, a given value of load was applied to the tendon. At this point, Hooke's law is obeyed i.e the tendon supports the load.
At point 2, the value of the load was increased and tendon obeys Hooke's law. This implies that as the load is increased, the the tendon was able to support it.
At point 3, a further increase in the value of load causes the elastic limit of the tendon to be exceeded. This means that the tendon would not return to its original shape and size if the load is removed, Hooke's law is no more obeyed.
At point 4, the tendon breaks because it can no longer sustain any value of load.
Help me out on this? Grades due in a couple days and I need to get everything done on time-
Answer:
75mL
...............
The question is full of inconsistencies and conceptual errors. Students should not waste their time trying to answer it ... it will only mislead and confuse them.
The question is poor. It was written by someone unclear on the concepts. It should be ignored.
A boat crosses a 200 m wide river at 3 ms-1, north relative to water. The river flows at 1 ms-1 as shown.
What is the velocity of the boat as observed by a stationary observer on the river back from which the boat departed?
Answer:
3.16 m·s⁻¹ at an angle of 71.6°
Explanation:
Assume that the diagram is like Fig. 1 below.
The boat is heading straight across the river and the current is directed straight downstream.
We have two vectors at right angles to each other.
1. Calculate the magnitude of the resultant
We can use the Pythagorean theorem (Fig. 2).
R² = (3 m·s⁻¹)² + (1 m·s⁻¹)² = 9 m²·s⁻² + 1 m²·s⁻² = 10 m²·s⁻²
R = √(10 m²·s⁻²) ≈ 3.16 m·s⁻¹
2. Calculate the direction of the resultant
The direction of the resultant is the counterclockwise angle (θ) that it makes with due East .
tanθ = opposite/adjacent = 3/1 = 3
θ = arctan 3 = 71.6°
To an observer at point O, the velocity of the boat is 3.16 m·s⁻¹ at an angle of 71.6°.
As a prank, your friends have kidnapped you in your sleep, and transported you out onto the ice covering a local pond. Since you're an engineer, the first thing you do when you wake up is drill a small hole in the ice and estimate the ice to be 6.7cm thick and the distance to the closest shore to be 30.5 m. The ice is so slippery (i.e. frictionless) that you cannot seem to get yourself moving. You realize that you can use Newton's third law to your advantage, and choose to throw the heaviest thing you have, one boot, in order to get yourself moving. Take your weight to be 588 N. (Lucky for you that, as an engineer, you sleep with your knife in your pocket and your boots on.)
1)(a) What direction should you throw your boot so that you will most quickly reach the shore? away from the closest shore perpendicular to the closest shore straight up in the air at your friend standing on the closest shore
2)(b) If you throw your 1.08-kg boot with an average force of 391 N, and the throw takes 0.576 s (the time interval over which you apply the force), what is the magnitude of the force that the boot exerts on you? (Assume constant acceleration.)
391 N
3)(c) How long does it take you to reach shore, including the short time in which you were throwing the boot?
Just number 3
Answer:
1a) The direction to throw the boot is directly away from the closest shore.
2b) The magnitude of the force that the thrown boot exerts on the engineer = 391 N
3c) Time taken to reach shore = 8.414 s
Explanation:
1a) Newton's third law of motion explains that for every action, there is an equal and opposite reaction.
The force generated by throwing the boot in one direction is exerted back on the engineer as recoil in the opposite direction.
Hence, the best direction to throw the boot is opposite the direction that the engineer intends to move towards.
2b) Just as explained in (1a) above, the force exerted in one direction always has a reaction of the same magnitude in the opposite direction.
Hence, the force exerted by the boot on the engineer is equal to the force exerted by the engineer on the boot = 391 N.
3c) For this part, we analyze the total motion of the engineer.
The force exerted by the boot on the engineer initially accelerates the engineer until the engineer reaches a constant velocity dictated the impulse of the initial force (since impulse is equal to change in momentum), this constant velocity then takes the engineer all the way to shore, since the ice surface is frictionless.
The weight of the engineer = W = 588 N
W = mg
Mass of the engineer = (W/g) = (588/9.8) = 60 kg
Force exerted on the engineer by the thrown boot = F = 391 N
F = ma
Initial acceleration of the engineer = (F/m) = (391/60) = 6.52 m/s²
We can then calculate the distance covered during this acceleration
X₁ = ut + ½at₁²
u = initial velocity of the engineer = 0 m/s (the engineer was initially at rest)
t₁ = time during which the force acts = 0.576 s
a = acceleration during this period = 6.52 m/s²
X₁ = 0 + 0.5×6.52×0.576² = 1.08 m
For the second part of the engineer's motion, the velocity becomes constant.
So, we first calculate this constant velocity
Impulse = Change in momentum
F×t = mv - mu
F = Force causing motion = 391 N
t = time during which the force acts = 0.576 s
m = mass of the engineer = 60 kg
v = final constant velocity of the engineer = ?
u = initial velocity of the engineer = 0 m/s
391 × 0.576 = 60v
v = (391×0.576/60) = 3.7536 m/s.
The distance from the engineer's initial position to shore is given as 30.5 m
The engineer covers 1.08 m during the time the force causing motion was acting.
The remaining distance = X₂ = 30.5 - 1.08 = 29.42 m
We can then calculate the time taken to cover the remaining distance, 29.42 m at constant velocity of 3.7536 m/s
X₂ = vt₂
t₂ = (X₂/v) = (29.42/3.7536) = 7.838 s
Time taken to reach shore = t₁ + t₂ = 0.576 + 7.838 = 8.414 s
Hope this Helps!!!
HELP 75 POINTS ON THE LINE MULTIPLE CHOICE!
At the top of its arc, a thrown ball has ______ potential energy and _______kinetic energy.
A) zero, maximum
B) maximum, maximum
C) maximum, zero
D) minimum, maximum
Answer:
C
Explanation:
because at the top there is the greatest energy stored(potential energy)
so its maximum, and minimum
A charge of 35.0 μC is placed on conducting sphere A of radius 8.00 cm. Another identical conducting sphere B (radius 8.00 cm) carrying 65.0 uC of charge is placed such that its center is 40.0 cm away from the center of the first sphere (A). a. If the two conducting spheres are now connected by a thin conducting wire, what are the new charges on the spheres? b. Now, the conducting wire is cut and the spheres are released from rest. What are their speeds when they are far apart (infinite distance away) from each other? Take the mass of each conductor to be 80.0 grams. Ignore gravity. Assume that the potential is zero at infinity.
Answer:
a) 50μC
b) 37.45 m/s
Explanation:
a) If the spheres are connected the charge in both spheres tends to be equal. This because is the situation of minimum energy.
Thus, you have:
[tex]Q_T=35\mu C+65\mu C=100\mu C\\\\Q_s=\frac{Q_T}{2}=50\mu C[/tex]
Hence, each sphere has a charge of 50μC.
b) You use the fact that the total work done by the electric force is equal to the change in the kinetic energy of the sphere. Then, you use the following equations:
[tex]\Delta W=\Delta K\\\\\int_{0.4}^\infty Fdr=\frac{1}{2}m[v^2-v_o^2]\\\\F=k\frac{Q^2}{r^2}\\\\v_o=0m/s\\\\m=0.08kg\\\\kQ^2\int_{0.4}^{\infty} \frac{dr}{r^2}=kQ^2[-\frac{1}{r}]_{0.4}^{\infty}=\frac{kQ^2}{0.4m}=\frac{(8.98*10^9Nm^2/C^2)(50*10^{-6}C)^2}{0.4m}\\\\kQ^2\int_{0.4}^{\infty} \frac{dr}{r^2}=56.125J[/tex]
where you have used the Coulomb constant = 8.98*10^9 Nm^2/C^2
Next, you equal the total work to the change in K:
[tex]\frac{1}{2}mv^2=56.125J\\\\v=\sqrt{\frac{2(56.125J)}{m}}=\sqrt{\frac{2(56.125J)}{0.08kg}}=37.45\frac{m}{s}[/tex]
hence, the speed of the spheres is 37.45 m/s
An infected tooth forms an abscess (area of infected tissue) that fills with gas. The abscess puts pressure on the nerve of the tooth, causing a toothache. While waiting to see a dentist, the person with the toothache tried to relieve the pain by treating the infected area with moist heat. Will this treatment help? Why or why not?
Answer:
No, the treatment won't work
Explanation:
Since the abscess is filled with gas, and is already putting pressure on the tooth nerve, applying moist heat will only aggravate the problem. The pressure of a given gas increases with temperature and so, the gas within the abscess will only put more pressure on the nerve due to the expansion of the gas within the abcess, causing her more discomfort.
A painter on a ladder, painting the ceiling of a room comments. “It is hotter up here by the ceiling than it is down on the floor”. Explain why his observation is correct.
Answer:
1. Hot air is less dense and has moved upward allowing cool air to move downward which is less dens
(Convection current)
2. The ceiling has transferred heat to him by radiation.
Explanation:
During the day when air is heated as a result of the ceiling transferring heat to it, it becomes less dens and it gains energy, which make it lighter in weight than cooler air, this hot air moves upward allowing cooler air to move downward.
Many pigeons live near Martyn’s air conditioning vents. Martyn isn’t able to clean the vents properly, and they often contain dried pigeon droppings. Martyn eventually falls sick with a respiratory illness. Which mode of disease transmission most likely made Martyn sick? A. oral B. aerosol C. vector D. fomite E. direct contact
Answer:
B) Aerosol
The particles from the pigeon droppings are likely to be transmitted from the air vents directly into Martyn's respiratory system
Answer:
aerosol
Explanation:
Avery took a wave motion rope and waved it sideways once. What kind of wave did Avery create, transverse, longitudinal, or a pulse?
Answer: transverse wave.
Explanation:
In a wave motion rope, the particles of the rope move in the perpendicular direction to the actual wave, so this is a transverse wave. (we have a longitudinal wave when the movement of the particles is in the same direction than the wave propagation, an example of this is the waves in the surface of the water when you throw a rock in)
Now, the fact that he waved it only once does not mean that this is a pulse if the other end of the rope is connected to a fixed point when the wave reaches that point will be reflected (losing a bit of amplitude, but we still will have a wave)
so the correct option is a transverse wave.
Explain why you cannot charge one end of a steel rod and
leave the other end uncharged.
Answer:
Because a steel rod is a good conductor which would make the charges produced to cascade easily from one end of the metal to another.
Explanation:
Charges are formed whenever an object gains or losses an electron. This can be easily produced by three major methods; friction, contact and induction.
Conductors, e.g metals (steel), are materials that would allow charges, electric current, or heat to flow through them easily. They have low resistance.
When a steel rod is charged at one end, the charges cascades from that end towards the other end because of the conducting property of the metal. Thereby it is very difficult to charge one end of the steel rod, while the other remains uncharged.
Which landscape will erode more quickly? Assume the same precipitation and average temperature in each landscape.
A. Landscape A.
B. Landscape B.
C. The rates of erosion will be the same.
D. Impossible to determine.
Answer:
B. Landscape B
Explanation:
Shale is fine sediment pressed together to form rock.
Sandstone is larger (sand-grain-sized) sediment cemented together to form rock.
Shale erodes faster, as evidenced by the second attachment. That attachment shows erosion of a rock face consisting of interbedded shale and sandstone. The shale has receded significantly, leaving the sandstone layers with space between them.