The x and y components of vector b are given as: ax = -2 m ay = 4 m. (a) what is the direction (in degrees) of the vector b?
the direction is represented by a counterclockwise angle from the +xaxis
(b) what is the direction (in degrees) of the vector -3b?

F500 j of energy were added to 1 kg of each of these samples, which would experience the least temperature increase?

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

How would a small bar magnet be oriented when placed at position x?