Select the correct answer.
What accounts for an increase in the temperature of a gas that is kept at constant volume?
O A. Energy has been removed as heat from the gas.
OB. Energy has been added as heat to the gas.
OC. Energy has been removed as work done by the gas.
OD. Energy has been added as work done by the gas.

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

Which body is in equilibrium? (1) a satellite orbiting earth in a circular orbit (2) a ball falling freely toward the surface of earth (3) a car moving with a constant speed along a straight, level road (4) a projectile at the highest point in its trajectory