1. Bend your elbow and place your hand at your ear, so that your forearm is

Question

1. Bend your elbow and place your hand at your ear, so that your forearm is

perpendicular to your face. 2. Stack the quarter(s) on the flat portion of your elbow. 3. Throw your arm forward slowly and try to catch the coins with the same hand. 4. Repeat, this time moving your arm quickly enough to catch the coins. 5. Compare the results from the slow and fast trial. 6. Explain which of Newton's Laws this activity demonstrates?

Answer 1

This activity demonstrates Newton's Third Law, which states that for every action, there is an equal and opposite reaction. In this case, when the arm is thrown forward quickly, the force applied to the coins causes them to stay on the flat portion of the elbow due to an equal and opposite force acting back on the arm. When the arm is thrown forward slowly, there is not enough force to counteract the force of gravity acting on the coins, causing them to fall off the elbow.