Why don't satellites in orbit fall to the ground? why don't the fly off into space?

What properties of a moving object are used in determining the object's energy of motion

If the spring constant k of a pogo stick is 3500 n m and the weight of the person on the pogo stick is 700 n, how much is the spring in the botom of the pogo stick compressed?

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.