Newton’s third law of motion is often stated as, “For every action, there is an equal and opposite reaction.” Place an X to the left of each of the statements below where the described forces are examples of Newton’s third law: A. You push on a tree with your hand and the tree pushes back on your hand.

B. A small car tows a large truck and they move at a constant speed. The truck pulls back the car and the car pulls on the truck.

C. A small car tows a large truck and they speed up. The truck pulls back on the car and the car pulls on the truck.

D. The Earth pulls down on you (your weight) and the floor pushes up on you.

E. Billy pushes Johnny and causes Johnny to fall down. Johnny exerts a force on Billy and Billy exerts a force on Johnny.

F. You pull on the door of the classroom and the door opens. Your hand exerts a force on the door and the door exerts a force on your hand.

G. A horse is pulling on a cart and the cart is speeding up. The horse exerts a force on the cart and the cart exerts a force on the horse.

H. You hold up a book against the wall. You apply a force to the book and the wall applies a force on the book.