Which of the following statements about an apple falling from a tree is true? a) its kinetic energy decreases and its potential energy increases. b) its potential energy decreases and its kinetic energy increases. c) its kinetic and potential energies remain constant. d) its mechanical energy increases.

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s.calculate eddy’s power rating

Aperson standing in a canoe exerts a force of 700 n to throw an anchor over the side. find the acceleration of the canoe if the total mass of the canoe and the person is 100 kg?