7. A single photon, from an unpolarized source, traveling in the z direction is directed through a series of three polarizers: first a polarizer with its axis in the x direction, then a polarizer at 25 degrees to the x direction, then finally a y polarizer.

a) What is the probability that the photon makes it through the first (x) polarizer and what is the photon’s polarization after it comes through the first polarizer?

b) For a photon that got through the first (x) polarizer, what is the probability that that photon goes through the next two polarizers and what is the photon’s polarization after it comes through the last polarizer?

c) If the middle (25 degree) polarizer is removed, what is the probability that the photon gets through both (remaining) polarizers?

Bob lifts a 0.9kg cup of coffee, initially at rest on the table, up to his mouth. The cup comes to rest after a vertical displacement of 0.7m. (NO IMAGE GIVEN)

a. In the process of being lifted, how much work was done on the cup by Bob?

b. Bob then hold the cup stationary for 1.8s. How much work was done on the cup by Bob during this time?

c. Realizing that the cup is empty, Bob lowers the cup 1.1m downward into the sink, where it comes to rest. How much work was done on the cup by Bob in the process of being lowered?

A. What is the moment of inertia of a solid iron sphere 20 inches in diameter about an axis passing through the sphere half way from its center to the surface (you will have to look up its density)? If the sphere rolls down an incline plane that makes an angle 20 degrees with the horizontal, what will be its acceleration?

B. Derive the formula for acceleration of a circular disk that rolls down an inclined plane that makes an angle θ with the horizontal. (draw a diagram and say in words what you are doing)

How to determine particle size using UV Visible spectroscopy

A football is kicked at ground level with a speed of 25 m/s at an angle of 45 degrees to the horizontal. How far down field does it go (assume takeoff and landing at the same height)?

A boy shoves his stuffed toy zebra, which has mass m, down a frictionless chute, starting at a height D above the bottom of the chute and with an initial speed of v. The toy animal emerges horizontally from the bottom of the chute and continues sliding along a horizontal surface with coefficient of kinetic friction μ. At what distance d from the bottom of the chute does the toy zebra come to rest? Express your answer in terms of the given variables and g, the acceleration due to gravity.

I thought the answer was (0.5v^2+gh)/(mu x g) but it is not correct apparently

Blocks A (mass 5.00 kg ) and B (mass 9.00 kg ) move on a frictionless, horizontal surface. Initially, block B is at rest and block A is moving toward it at 2.00 m/s . The blocks are equipped with ideal spring bumpers. The collision is head-on, so all motion before and after the collision is along a straight line. Let +x be the direction of the initial motion of block A.

a.) Find the maximum energy stored In the spring bumpers.

b.) Find the velocity of block A when the energy stored in the spring bumpers is maximum.

c.) Find the velocity of block B when the energy stored in the spring bumpers is maximum.

d.) Find the velocity of block A after they have moved apart.

e.) Find the velocity of B after they have moved apart.

Draw how the negative and positive charges are distributed for DC and AC plasmas

A bullet of mass 0.010 kg and speed of 100 m/s is brought to rest in a wooden block

after penetrating a distance of 0.10 m. The work done on the bullet by the block is

A.

50 J.

B.

-

50 J.

C.

0.001 J.

D.

-

0.001 J.

E.

zero.

A helium-filled balloon is attached to one en of a uniform wooden beam, lifting it partially up off of the ground. The beam is 2.25 meters long and it weighs 578N. What Volume of helium is required to hold the beam up at an angle of 30.0⁰ ? (You can ignore the weight of the empty balloon and the wire connecting it to the beam.)

2. As seen from Earth, two spaceships A and B are approaching along perpendicular directions. Spaceship A is observed by an Earth observer to have velocity uy = −0.60c and spaceship B to have a velocity ux = −0.80c. Find the magnitude of the relative velocity of the two spaceships by transforming the velocity of one ship into the rest frame of the other. Remember, the answer has to be less than c.

Why does the weight of an object in the air differ from its weight in a vacuum (remembering that weight is the force exerted against a supporting surface)? Cite an example in which this would be an important consideration.

3. A proton is accelerated in a Van de Graff through a potential difference of 4 million Volts.

a. What is its its total energy after acceleration?

b. What is the magnitude of its final momentum?

c. What is its velocity?

A helium-filled balloon has a volume of 0.010 m3. The temperature in the room and in the balloon is 20 C What are the average speed of a particle of helium inside the balloon? What is the thermal energy of the helium in the balloon? Assume that due to stretching of the balloon the pressure inside it is 1.1 atm.