Todd purchased a jumper for his infant son. The jumper clamps to the top of the door frame and a spring in which the body of the jumper hangs to allow the infant to jump up and down. Included in the jumper are weights, each identical in weight and size. The weights allow the user to adjust the initial height of the jumper by stretching the springs a certain distance. Todd adds 8 of the weights and notes the springs stretches 2 centimeter.

a. According to Hook's law the amount that the 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.

b. Use your equation from part a, find the number of weights necessary for the spring to stretch 7 centimeters.

A) We are told that according to Hook's law, the amount that the spring is stretched, s, varies directly with the force applied to the spring by the weights. This can be represented as;

F ∝ s

Now, there is a constant of proportionality here that will make this a relatable equation and this is k. Thus, the equation that relates F and s for the spring on the jumper is; F = ks

B) Initially, we are told that 8 of the weights produces a stretch of 0.02 m. Thus;

8 = 0.02k

k = 8/0.02

k = 400 weights/m

To now find the number of weights necessary for the spring to stretch 7 centimeters or 0.07 m, we will have;

F = 400 × 0.07

F = 28 weights

Read more about hooke's law at; https://brainly.com/question/25711925