Felipe is riding his skateboard toward lilah at 15 km/h. he throws a football to lilah. the football is thrown at 8 km/h. how fast is the football traveling when it reaches lilah?

How would doubling the made of an object change the objects potential energy

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.

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