PHYSICS 1B Final: Compiled TA Review Session Notes (Emmel)

(a) At what times t > 0 will plate A again have maximum positivecharge (n = 1, 2, 3, 4, ...)? (Answer in terms of n.)
ta = µs
(b) At what times will the other plate of the capacitor havemaximum positive charge?
tb = µs
(c) At what times will the inductor have the maximum magnitude ofmagnetic field?
tc = µs

1. A 670 kg meteorite happens to be composed of aluminum. When itis far from earth, its temperature is -15 degrees Celsius and itmoves with a speed of 14 km/s relative to the earth. As it crashesinto the planet, assume that the resulting additional internalenergy is shared equally between the meteor and the planet, andthat all of the material of the meteor rises momentarily to thesame final temperature. Find this temperature. Assume that thespecific heat of liquid and gaseous aluminum is 1170 J/kgC.

2. The inside of a hollow cylinder is maintained at a temperature(Ta) while the outside is at a lower temperature (Tb). The wall ofthe cylinder has a thermal conductivity k. Ignoring end effectsshow the rate of energy conduction from the inner to the outersurface in the radial direction is:

dQ/dt =( 2(3.14)(L)(k)) (Ta-Tb/ln(b/a))

At an airport, luggage is unloaded from a plane into the three carsof a luggage carrier, as the drawing shows. The acceleration of thecarrier is 0.13 m /s2, and friction is negligible. The couplingbars have negligible mass.
(a) By how much would the tension in each of the coupling bars A,B, and C change if 32 kg of luggage were removed from car 3 andplaced in car 1? If the tension changes, specify whether itincreases or decreases. (Specify a decrease in tension with anegative value and an increase in tension with a positive value. Ifthere is no change, enter 0.)
?TA= N
?TB= N
?TC= N

(b) By how much would the tension in each of the coupling bars A,B, and C change if 32 kg of luggage were removed from car 1 andplaced car 2? If the tension changes, specify whether it increasesor decreases. (Specify a decrease in tension with a negative valueand an increase in tension with a positive value. If there is nochange, enter 0.)
?TA= N
?TB= N
?TC= N