Two lenses are separated by L = 50.0 cm. The first lens (light coming from the left.) has a focal length f1 = 24.0 cm and the second lens has a focal length f2 = 18.0 cm. An object is located 40.0 cm (s1) to the left of the first lens. Calculate the position of the two images formed by the lens system. State whether each image is real or virtual. Repeat this problem with L = 10.0 cm.

Four identical point charges of magnitude q = 3.2 nC are placed at the corners of a rhombus of edge length l = 22 cm and obtuse angle θ. We intentionally leave θ undefined. Find the net electric force on each of the four charges. Your answer will depend on the angleθ. For convenience, orient your rhombus so that the charges are placed at (±x, 0) and (0, ±y).

1

Write a few sentences addressing each of these prompts.

1. In your own words, what is the difference between electric force, electric field, and electric charge? You may find it easier to describe how the three concepts are related.

2. If two charges are observed to repel one another, what can you say about the sign of each? What if the two attract one another? With only this information (whether they attract or repel) can you identify which charge is which type (positive or negative)? What does this mean about the assignment of “positive” or “negative” charge?

3. In a very contrived situation, two students are discussing the following problem.

   “A point charge of 2 μC is placed in an electric field and experiences a force of 27 N. Find the electric field. The 2 μC charge is removed and replaced with a 4 μC charge. What is the electric field now?”

   One student insists the field is 13.5 N/C in both cases and the other says it is 13.5 N/C in the first case and 6.75 N/C in the second case. Why might each student take their stated position and which one is correct? Provide an argument based on the physics that could help the incorrect student see their error.

A thin nonconducting rod with a uniform distribution of positive charge Q is bent into a circle of radius R (see the figure). The central perpendicular axis through the ring is a z axis, with the origin at the center of the ring. What is the magnitude of the electric field due to the rod at (a) z = 0 and (b) z = ∞? (c) In terms of R, at what positive value of z is that magnitude maximum? (d) If R = 2.20 cm and Q = 4.30 μC, what is the maximum magnitude?

Assume that mountains higher than 10 km do not exist on Earth because bigger mountains could not be supported by the strength of rock at their bases. The pressure at the middle of the base of a mountain is equal to the weight of a column of rock (with unit cross section area) as high as the mountain. The pressure at the base of taller mountains would exceed the strength of the rock and the mountain would slump.

For rock of identical density (3000 kg m-3 ) and crushing strength, determine the maximum size cubic asteroid that could you could make out of two identical blocks with dimensions of L, L and L/2. The two blocks put together make a cube.

For a larger sized asteroid, the pressure between cubes caused by gravitational attraction would exceed the rock’s yield strength and it would flow - forming a more spherical shape. For calculation you can assume that the mass of block is concentrated at its center so that the pressure between the two blocks is just the force between the centers of mass divided by the contact area.

You have three capacitors: C1 = 1500. μF, C2 = 2400. μF, and C3 = 3600. μF. Find Ceq for a) all in series b) all in parallel c) c1 and c2 are in parallel and c3 in series with them d) c2 and c3 in parallel and R1 in series with them, e)c1 and c3 in parallel and c2 in series with them. f) For one of the three arrangements where only two of the caps are connected in parallel, calculate the ∆V ’s and Q’s for each capacitor in that arrangement, if connected to a E = 12.00 V EMF.

1.00 moles of a gas is at a temperature of 273 Kelvin and has a pressure of 1.00x10⁵Pa.

1. What is its initial volume?
2. STEP 1: Its pressure is doubled while keeping its volume constant. What is its temperature after this step?
3. STEP 2: Its temperature is held constant while it it is reduced back to its initial pressure. What is the the volume after this step?
4. Draw a PV diagram showing the two step (it doesn’t have to have numbers, just qualitatively correct)
5. What is the work done by the 2 Steps (in Joules)?

When energy enters your home does the energy need to be charged from ac to dc first before entering your phone or dc to ac? Not sure if I am asking this right but what is the basic idea behind how energy comes from a power plant to charge my cell phone?

Describe an experiment using an ideal calorimeter.

Givens (Questions 1

A drinking fountain shoots water about 14 cm up in the air from a nozzle of diameter 0.60 cm. The pump at the base of the unit (1.1 m below the nozzle) pushes water into 1.2 cm diameter supply pipe that goes up to the nozzle. What gauge pressure does the pump have to provide? Ignore the viscosity; your answer will therefore be an underestimate

A photon propagating in the x direction with an energy of 1.00 Mev is incident on a free electron and Compton scattering occurs so that the scattered photon makes an angle of 60.0° with the x axis.

A) Find the energy of the scattered photon.

B) Find the kinetic energy of the scattered electron.

C) Find the x component of the momentum for the scattered electron

A cube has sides of length L = 1.00 mm. One corner is at the origin. The nonuniform electric
field is given by E~ = (19.00N/C ·m) x ˆi−(1.34N/C ·m) z
ˆk. (a) find the electric flux through
each of the six cube faces S1, S2, S3, S4, S5, S6. (b) Find the total electric charge inside the
cube.

A wire containing a charge of λ Coulombs per unit length is embedded along the axis of a cylinder of dielectric material. There is no free charge inside the dielectric. The composition of the dielectric is non-uniform, such that its permittivity is a function of the distance from the central axis, i.e. ε = ε(r).

(a) Find the displacement field, D as a function of distance from the central axis of the wire, r.

(b) if the electric field strength, E, is independent of r, determine the form of ε(r).

(c) Find an expression for the electrostatic potential as a function of r.

A 7.2 kg block with a speed of 10 m/s collides with a 19 kg block that has a speed of 5.4 m/s in the same direction. After the collision, the 19 kg block is observed to be traveling in the original direction with a speed of 5.4 m/s. (a) What is the velocity of the 7.2 kg block immediately after the collision?(b) By how much does the total kinetic energy of the system of two blocks change because of the collision? (c) Suppose, instead, that the 19 kg block ends up with a speed of 4.7 m/s. What then is the change in the total kinetic energy?