The police use radar guns and the Doppler effect to catch violators. A police car is driving from right to left at 60 km/h, another man's car is approaching the police car, from left to right, at a speed of 130 km/h. A police-powered radar gun emits an electromagnetic wave whose frequency is 8 x 10^9 Hz that is reflected from the oncoming car.

a) What is the difference between the frequency of the wave emitted by the gun and the frequency received by the man's car?

b) What is the difference between the frequency of the wave emitted by the gun and the frequency that returns to the police car?

The table below shows how much of the mass of the Sun and the Earth are made up of each element (by mass). Note that, for this problem, the amounts have been randomized somewhat from their real values. For your answers to this problem, use the values given in the table below. Note that because of rounding, uncertainties in the known values, the applied randomization, and small differences between the solar nebula composition and the composition of the Sun, it is possible to have answers more than 100%.

Assume that all of the iron in the solar nebula in the Earth's vicinity was incorporated into the Earth. Use the data in the table to calculate what percentages of the available silicon, sulfur, and oxygen were incorporated.

The percentage of silicon is  %.

The percentage of oxygen is  %.

The percentage of sulfur is  %.

please answer all qustions and all parts and make sure you have the right answers.

1. An electric field is given by E_x = 3.5x³ kN/C. Find the potential difference between the points on the x axis at x = 1 m and x = 3 m.

..... kV

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2. (a) Find the maximum net charge that can be placed on a spherical conductor of radius 12 cm before dielectric breakdown of the air occurs.
.... µC

(b) What is the potential of the sphere when it carries this maximum charge?
..... kV

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3. Consider an electron and a proton that are initially at rest and are separated by 1.20 nm. Neglecting any motion of the much more massive proton.

(a) What is the minimum kinetic energy with which the electron must be projected so it reaches a point a distance of 26.0 nm from the proton? Assume the electron's velocity is directed radially away from the proton.
..... J

(b) What is the electron's speed at this energy?
..... m/s

The height to which a ball bounces after being dropped provides a measure of how much energy is lost in the collision with the floor or other surface. A small portion of energy is lost to air resistance as the ball is moving, but most is lost in the collision.

1. Trying a number of different balls that you that you may have available, test the height of the bounce using the same height or release for all of the balls tested. Which ball loses the most energy and which is the least?

2. Can you explain why many balls return to a higher height than a marble will? What characteristics of the balls tested give the best bounce?

3. For a ball that bounces several times, does the period (time between bounces) change with each bounce? (Again, recording a video would help tremendously. Make sure your camera is held still and a meter stick or some other object of known height is within the frame, but does not obstruct the motion)

4. Can you predict how the bounce height would change if your release height is doubled? Halved?

5. Try it, observe, measure and record your results. 6. Does the bouncing ball undergo simple harmonic motion? Why or why not?

A tetherball swings around a pole, making a full circle once every 2s. The total length of the rope is 2 m. Calculate the angle θ that the rope makes with the pole. The rope has negligible mass.

14. Students Norma Lee and Rangh are discussing force and motion as discussed in class.

(The question didn't specify if the speed is constant or not, please list both possibilities.) Norma is describing the motion of a cart on a level frictionless track and identifying the

forces acting on the cart. She has listed gravity, the track pushing upward and a push in

the direction of motion as acting when the cart is coasting down the track.

Lee is puzzling over a case of circular motion and how a ball moving in a circle with constant

speed can have a net force acting when the speed is not changing.

  Rangh replies that it might help if they consider what object is exerting each force.

Analyze the three students’ statements, identifying what is wrong or right BASED ON YOUR LAB EXPERIENCE AND DATA and knowledge of physics principles.

Proof the equation of number of holes in VB at intrinsic Semiconductor

A straight metal wire is placed between the poles of a magnet, as shown in the figure. Magnetic field is uniform in the space between the poles. If there is a current I flowing through this wire in the direction from C to A, what is the direction of the magnetic force acting on the wire?

in air track experiments, we assume that kinetic friction between the ait track and the car is negligible. If friction is not negligable, how would the friction affect each of the following

A) velocity of the car

B) kinetic energy of the car

C) potential energy of the car

D) mechanical energy of the car

As shown below, a 100 kg student is compressed 50 cm on a spring with a spring constant of k = 80,000 N/m. He is on top of a 10 m frictionless hill. He then is released from rest. He goes down to the bottom of the hill before sliding up a 30° frictionless hill. a. (8 pts) Find the speed of the student when he reaches the bottom of the hill. b. (9 pts) Find the distance D the student travels up the hill before momentarily stopping. Use whichever method you wish.

A cooling fan is turned off when it is running at 840 rev/min . It turns 500 revolutions before it comes to a stop.

1.) What was the fan's angular acceleration, assumed constant?

2.) How long did it take the fan to come to a complete stop?

A) A 12.0-g bullet is fired horizontally into a 113-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 149 N/m. The bullet becomes embedded in the block. If the bullet-block system compresses the spring by a maximum of 76.0 cm, what was the speed of the bullet at impact with the block?

B)A 0.033-kg bullet is fired vertically at 238 m/s into a 0.15-kg baseball that is initially at rest. How high does the combined bullet and baseball rise after the collision, assuming the bullet embeds itself in the ball?

Explain and solve the following physics question.

An alpha particle with kinetic energy 14.0 MeV makes a collision with lead nucleus, but it is not "aimed" at the center of the lead nucleus, and has an initial nonzero angular momentum (with respect to the stationary lead nucleus) of magnitude L=p0b, where p0 is the magnitude of the initial momentum of the alpha particle and b=1.20×10⁻¹² m . (Assume that the lead nucleus remains stationary and that it may be treated as a point charge. The atomic number of lead is 82. The alpha particle is a helium nucleus, with atomic number 2.)

1. What is the distance of closest approach? Find r. (meters)

2. Repeat for b =1.30×10⁻¹³ m. Find r. (meters)

3. Repeat for b =1.30×10⁻¹⁴ m. (meters)

A rider on a Ferris wheel shown below travels at a constant speed. Is the rider’s apparent weight of the rider greater at the top or the bottom? Explain using physical reasoning and FBDs if necessary.