A merry-go-round accelerates from rest to 0.74 rad/s in 34 s.

Part A

Assuming the merry-go-round is a uniform disk of radius 8.0 m and mass 3.20×10⁴ kg , calculate the net torque required to accelerate it.

Express your answer to two significant figures and include the appropriate units

A monatomic ideal gas is heated while at a constant volume of 1.00 * 10^-3 m^3, using a 10 watt heater. The pressure of the gas increases by 5.0 * 10^4 Pa. How long was the heater on?

As everybody knows that Black objects are black because almost all the light that falls on them is absorbed into the material. Little or no light is reflected back toward our eyes, therefore we see black.

It is also known that, since black objects absorbs all the light they ultimately become heated-up..!

If we see the snow in visible light, It appears to be White. But in the Infrared, it appears to be black. Does that mean that the Snow will feel warm in Infrared lights?

Consider a GaAs p-n junction diode. The p-type acceptor is Zn, with a dopant concentration of 2 x 10^17 cm^-3 and the n-tpye donor is Si, with a dopant concentration of 5 x 10^16 cm^-3. Working at temp= 300 K.

a) Calculate the Fermi Level in the p-type material. Assume that the hole density is equal to the density of the p-dopant atoms.

b) Performing the same calculation for the n-type material gives a fermi level of 1.363 eV. What is the zero-bias built- in potential at the junction?

c) Calculate the width of the depletion zone for this case

1.     a 10 g particle is undergoing simple harmonic motion with an amplitude of 2.0X10^-3 m and a maximum acceleration of magnitude 8.0X10^3 m/s^2. The phase constant is

Question 4.)

The Fermi Level Under Equilibrium Conditions is Constant. (True or False)

Question 6.) The Fermi level of a semiconductor doped with As (Group V) is : (choose one)

Above the valence band but below the middle of the bandgap.

Below the valence band edge.

Above the conduction band edge.

Above the middle of the bandgap and below the conduction band.

At the precise middle of the bandgap

15.) Choose all that applies for a semiconductor doped n-type:

It has more holes than electrons

Its fermi energy is located exactly at mid gap

Its conductivity depends on the amount of dopant added

It contains impurities

Its bandgap is smaller due to the doping

16.) Choose all that apply for an intrinsic semiconductor at room temperature

It has more holes than electrons

It has more electrons than holes

The Fermi level is located at midgap.

It has an equal number of electrons and holes

17.) Choose all that apply for a degenerate semiconductor:

It is excessively doped with donors or acceptors.

It must be n-type

It must be p-type

It's fermi energy is very close to the middle of the gap

20.) Diffusion currents can only exist in the presence of large electric fields (True or False)

An object is thrown straight up into the air. The object leaves the person’s hand with an upward velocity of magnitude 27 m/s. Assume that the object is in free fall, i.e., neglect air resistance. Draw a motion diagram and graphs (two graphs: one for vertical position vs. time, and one for vertical velocity vs. time) from the time when the object leaves the person’s hand to 5.0 seconds later. Include all the information on the graph that you can determine about the object’s motion, such as its position and velocity at 5.0 seconds. Assume that the person does not catch the object or interfere with it during the 5.0 seconds time interval.

(DETAILED EXPLANATION AND DRAWINGS/GRAPHS PLEASE)

A hockey stick exerts a horizontal force of magnitude 3.0 N on a 0.25-kg puck. While under the influence of the stick's force (and possibly some other forces), the puck moves 2.0 m. a) Is it possible that the stick does 6.0 J of work on the puck? If so, what is the angle between the stick's force and the puck's displacement while the force acts? b) Is it possible that the stick does - 3.0 J of work on the puck? If so, what is the angle between the stick's force and the puck's displacement? c) Is it possible that the stick does -6.0 J of work on the puck? If so, what is the angle between the stick's force and the puck's displacement? d) Is it possible that the stick does 6.0 J of work on the puck? If so, what is the angle between the stick's force and the puck's displacement? e) If the puck possesses an initial speed of 4.0 m/s, and then 4.0 J of work is done on the puck, find its final speed. Ignore friction. f) If the puck possesses an initial speed of 4.0 m/s, and then -2.0 J of work is done on the puck, find its final speed. Ignore friction.

A 765-kg two-stage rocket is traveling at a speed of 6.10×103 m/s away from Earth when a predesigned explosion separates the rocket into two sections of equal mass that then move with a speed of 2.30×103 m/s relative to each other along the original line of motion.

Part A

What is the speed of each section (relative to Earth) after the explosion?

Part B

How much energy was supplied by the explosion? [Hint: What is the change in kinetic energy as a result of the explosion?]

In his double-slit experiment with electrons, jonsson used electrons with kinetic energy 50 kev.

A) Find the electron's de Broglie wavelength

B) The two slits were separated by 2.0 um. On a screen 0.350m from the slits, what was the distance between bright diffraction fringes?

1- An object is rotating in a uniform circular motion. What can you say about:

a- Its angular velocity,

b- Its speed,

c- Its velocity,

d- Its acceleration.

e- periodic time.

f- having good tires in your car is very important, why?

I need answer asap

A 0.60 kg mass sliding on a horizontal frictionless surface is attached to one end of a horizontal spring (with k = 650 N/m) whose other end is fixed. The mass has a kinetic energy of 11.0 J as it passes through its equilibrium position (the point at which the spring force is zero).

A. At what rate is the spring doing work on the mass as the mass passes through its equilibrium position?

B. At what rate is the spring doing work on the mass when the spring is compressed 0.092 m and the mass is moving away from the equilibrium position?

An object rotates according to the following expression: θ(t) = 2.3t3 – 2t2 + 0.5t with θ in radians and time in seconds.

Find the average angular speed from t = 0 to t = 2 seconds.

Find the instantaneous angular speed of the object at t = 2 seconds.

Find the average angular acceleration from t = 0 to t = 2 seconds.

Find the instantaneous angular acceleration of the object at t = 2 seconds.

If the temperature stayed the same but the dew point decreased, would the lifted condensation level (LCL) height increase or decrease? (ii) If the temperature decreased, but the dew point stayed the same, would the LCL height increase or decrease? (iii) Based on your answers above, how does relative humidity relate to the LCL height? Explain your answer.

An experiment was performed to determine the efficiency of a transformer. A coil is placed into another coil, and a steel bar is placed on the inside of both coils.

f (efficiency) = V1*N2 / V2*N1

Suppose we ignore the possibility of someone having miscounted the number of turns. Why might "1 turn" (or, perhaps, "1/2 turn") still make sense as an uncertainty on the number of turns?