Chapter 11: Lesson 2

Changes in Motion

Newton's Laws

    Newtons second law says that the acceleration of an object depends on the objects net force and the objects mass. This includes acceleration. Acceleration is the change in speed, velocity, and direction. If you go bowling with a bowling ball and a ping-pong ball the bowling will knock down more pins because it has more mass.    Newtons third law says for every action force there is an equal and opposite reaction force.  An action force is a downward force and a reaction force is an upward push.  A gymnast jumps on a spring board to get onto the bars (action force) and the springs bounce her up. (reaction force)