A boy lifts a 30N toy car 2 meters above the ground. How much work did the boy do on the car?

Which type of current is produced by a wire breaking magnetic field lines and changing the polarity? a. alternating b. direct c. straight d. alternating and direct

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?