A 2-kg mass weighs 20 N and is held 4 m above the ground. Its potential energy relative to the ground is

An iron ball and wooden ball of the same size are dropped simultaneously from a tower and reach the ground at the same time. The iron ball has a greater

A quick jerk on a sheet of paper beneath a box of cereal doesn’t topple the box, which best illustrates that

A kilogram is a unit of

A circus diver drops from a high pole into water far below. When he is half-way down

At some point between Earth and the Moon, the forces due to gravity on a space traveler would be the same when this point is

A bird sitting on the limb of a tree is moving about 30 km/s with respect to the Sun. If the bird takes 1 second to drop down to a worm below, the worm would be 30 km downrange from the bird when it reached the ground. This faulty reasoning is best countered with Newton’s

Which of these is not a form of solar energy?

An iron ball is placed in a pie pan that floats in a bucket. The water level is marked at the side of the bucket. Then the iron ball is removed and allowed to sink in the bucket. The water line at the side of the bucket is

When you simultaneously drop a light tennis ball and a heavy bowling ball, they hit the floor