1. Todd purchased a jumper for his infant son. The jumper clamps to the top of a door frame and has a spring from which the body of the jumper hangs to allow the infant to jump up and down. Included with the jumper are small weights, each identical in weight and size. The weights allow the user to adjust the initial height of the jumper by stretching the spring a certain distance. Todd adds 8 of the weights and notes the spring stretches 2 centimeters.
(a) According to Hook's Law, the amount that a spring is stretched, s, varies directly with the force applied to the spring by the weights, $F$. Write an equation that relates F and s for the spring on the jumper. (3 points)

F=ks 8=k 2
k=8/2 F=4 x