Q.

Consider a silicon p-n junction solar cell of area 4 cm². If the doping of the solar cell are NA = 1.0x10¹⁶cm-3 and ND = 1.5x10¹⁹ cm-3 and given τn = 10 μs, τp = 0.5 μs, Dn = 9.3 cm2 /s, Dp = 2.5 cm2 /s and IL = 95 mA, (a) calculate and plot the I-V characteristics of the solar cell, (b) calculate the open-circuit voltage and (c) determine the maximum output power of the solar cell, all at room temperature.

Not having studied General Relativity, I have sometimes been puzzled by references to the behaviour for "classic" black holes

A large fish hangs from a spring balance supported from the roof of an elevator.

Part A

If the elevator has an upward acceleration of 2.90m/s2 and the balance reads 50.0N , what is the true weight of the fish?

Part B

Under what circumstances will the balance read 32.0N ?

Part C

What will the balance read if the elevator cable breaks?

The thickness of a single membrane is about 7 nm. A myelin sheath consists of multiple membranes produced by coils of Schwann cell or oligodendroglia cells. Suppose a myelin sheath results from 100 membranes stacked on top of each other.

A) What is the specific capacitance of the myelin?

B) If the myelin sheath is a right circular cylinder 1 mm long, what is its total capacitance?

C) How much charge does it take to produce a voltage of -70 mV across this capacitor?

D) If the myelin were just 1 membrane--i.e, not myelin--what would be its capacitance? How much charge would it take to produce a voltage of -70mV across the single membrane?

6) A meteor of mass 575 kg has speed 90.0 m/s when it is 800 km above the surface of the Earth. It is falling vertically and strikes a bed of sand in which it is brought to rest in 3.25 m. Ignore the effects of air resistance. a) What is its speed just before striking the sand? b) How much work does the sand do to stop the meteor? c) What is the average force exerted by the sand on the meteor? d) How much thermal energy is produced?

An 8.0 m, 280 N uniform ladder rests against a smooth wall. The coefficient of static friction between the ladder and the ground is 0.65, and the ladder makes a 50.0° angle with the ground. How far up the ladder can an 870 N person climb before the ladder begins to slip?

a 240lb man is standing on both feet. the contact area for each shoe is 4 inches by 12 inches. the area of contact for each shoe is 48 inches. what is the pressure exerted on the floor.

An object at rest on a flat, horizontal surface explodes into two fragments, one seven times as massive as the other. The heavier fragment slides 8.50m before stopping. How far does the lighter fragment slide?

Assume that both fragments have the same coefficient of kinetic friction.

A circular coil 20.0cm in diameter and containing nine loops lies flat on the ground. The Earth's magnetic field at this location has magnitude 8.00

A 575-g block is dropped onto a relaxed vertical spring that has a spring constant k =200.0 N/m. The block becomes attached to the spring and compresses the spring 58.1 cm before momentarily stopping. While the spring is being compressed, what work is done on the block by the gravitational force on it?What is the speed of the block just before it hits the spring? (Assume that friction is negligible.)

If the speed at impact is doubled, what is the maximum compression of the spring?

Interactive Solution 8.29 offers a model for this problem. The drive propeller of a ship starts from rest and accelerates at 2.31 x 10-3 rad/s2 for 2.44 x 103 s. For the next 1.00 x 103 s the propeller rotates at a constant angular speed. Then it decelerates at 2.09 x 10-3 rad/s2 until it slows (without reversing direction) to an angular speed of 2.22 rad/s. Find the total angular displacement of the propeller.

Atoms in a solid are not stationary, but vibrate about their equilibrium positions. Typically, the frequency of vibration is about f = 4.60 x 1012 Hz, and the amplitude is about 3.55 x 10-11 m. For a typical atom, what is its (a) maximum speed and (b) maximum acceleration?

A novelty clock has a 0.0104 kg mass object bouncing on a spring that has a force constant of 1.28 N/m. How many joules of kinetic energy does the object have at its maximum velocity if the object bounces 2.77 cm above and below its equilibrium position? What is the maximum velocity of the object in m/s? Show work.

why is a 1 dimensional spectral sequence not enough to classify stellar spectra?

When the car is skidding, does kinetic friction act on the tire?

When the car is not skidding(wheels rolling), does static friction act on the tire?

If so, explain why.