1. a) Describe the balance of forces that hold together the subatomic particles in the nuclei of atoms.

b) Explain the process of radioactive decay and how radioactive half-lives are used to find the age of certain materials.

A uniform electric field between two parallel plates has a magnitude of 20 N/C and directed downward. Draw the E-field indicating +/- signs which plate is positive and which plate is negative?

A .22 rifle bullet is fired in a horizontal direction with a muzzle velocity of 900 ft/sec. In the absence of air resistance, how far will it have dropped in traveling a horizontal distance of (a) 50 yd? (b) 100 yd? (c) 150 yd? (d) How far will it drop in one second?

A proton, moving with a velocity of vii, collides elastically with another proton that is initially at rest. Assuming that after the collision the speed of the initially moving proton is 1.60 times the speed of the proton initially at rest, find the following.

(a) the speed of each proton after the collision in terms of v_i

initially moving proton _______________ x v_i

initially at rest proton  _______________ x v_i

(b) the direction of the velocity vectors after the collision (assume that the initially moving proton scatters toward the positive y direction)

initially moving proton _______________ degrees relative to +x-axis

initially at rest proton  _______________ degrees relative to +x-axis

An ancient club is found that contains 130 g of pure carbon and has an activity of 6.5 decays per second. Determine its age assuming that in living trees the ratio of (14 C /12 C ) atoms is about 1.20 × 10^ − 12 . Note that the half life of carbon-14 is 5700 years and the Avogadro number is 6.02 × 10^23 .

3.3 L and C with non-vacuum filler

If we fill the space between the plates of a capacitor with an insulator the capacitance changes by a factor k called the dielectric constant due to a change in the electric field. A similar effect is observed if we fill the inner volume of a coil acting as a solenoid (the core of the solenoid), only the inductance changes due to a change in the magnetic field. Let us assume when we fill the core with some matter. The inductance will change from L to L

A solid metal ball is placed in an external electric field of magnitude 300    N/C. The electric field at the center of the ball is

   a. zero.               b. 300 N/C.
   c. 300 V/m.               d. 150 N/C.

(please show work)

This is given as a practice problem for an upcoming exam, can you please explain it with as much detail as possible?

A potter's wheel - a thick stone disk of radius .5m and mass 100kg - is freely rotating at 50 rev/min. The potter can stop the wheel in 6 s by pressing a wet rag against the rim and exerting a radially inward force of 70N.

a. Find the effective coefficient of kinetic friction between the wheel and the rag

b.What is the change in angular momentum of the potter's wheel?

c. If the angular momentum is conserved what happens to the angular momentum that used to be in the potter's wheel?

A 0.49 kg mass at the end of a spring vibrates 8.0 times per second with an amplitude of 0.10 m.

(a) Determine the velocity when it passes the equilibrium point.

m/s

(b) Determine the velocity when it is 0.10 m from equilibrium.

m/s

(c) Determine the total energy of the system.

J

(d) If the amplitude of oscillation were increased by a factor of 3.8, by what factor does the total energy change?

Discuss Blackbody radiation. What was done before Planck? What was wrong with it? What did Planck do differently? Be explicit about his assumptions. Draw a rough sketch of the spectrum of light emitted from a blackbody radiator at 200 K. You should be able to locate the maximum frequency. Now redo that sketch for double the temperature, that is 400 K.

You are lowering two boxes, one on top of the other, down the ramp shown in the figure (Figure 1) by pulling on a rope parallel to the surface of the ramp. Both boxes move together at a constant speed of 11.0 cm/s . The coefficient of kinetic friction between the ramp and the lower box is 0.430, and the coefficient of static friction between the two boxes is 0.838.

What is the magnitude f of the friction force on the upper box?

What force T do you need to exert to accomplish this?

3. How do the mechanisms that cause Type I and Type II supernovae explain their observed differences?

Please explain and write out clearly!

Soap bubbles appear to be a mixture of red and green colors when sunlight strikes the wall of a soap bubble at nearly normal incidence (red 700 nm, green 500 nm).
a) Explain how the soap bubble can look both red and green at the same time. In your explanation, answer whether this is due to constructive or destructive interference.
b) What is the thickness of the bubble wall if the inex of refraction of the bubble is 1.35?

Two point charges lie on the x axis. A charge of 6.5 μC is at the origin, and a charge of -9.2 μC is at x=10.0cm. What is the net electric field at x=−4.0cm? What is the net electric field at x=+4.0cm?Express your answer using two significant figures. Express your answer using two significant figures.

A 310 g block is dropped onto a relaxed vertical spring that has a spring constant of k = 2.2 N/cm (see the figure). The block becomes attached to the spring and compresses the spring 16 cm before momentarily stopping. While the spring is being compressed, what work is done on the block by (a) the gravitational force on it and (b) the spring force? (c) What is the speed of the block just before it hits the spring? (Assume that friction is negligible.) (d) If the speed at impact is doubled, what is the maximum compression of the spring?