Long cardboard tube, such as an empty roll of wrapping paper, to make your ramp. It should be at least two-and-one-half feet long. A thin book or small wood block to raise one end of your ramp. It ...

Velocity-time graphs show how the velocity (or speed) of a moving object changes with time. These graphs also show if the object is moving at a constant speed or accelerating, decelerating, or still.

I had an interesting thought, spurred on by a discussion I ran across online about firing guns in space. Apparently, smokeless powder contains its own oxidizer and so you could shoot normal firearms ...