Chapter P.2, Problem 9P

The following passages and associated questions are based on the material of Part II.

Big Air

A new generation of pogo sticks lets a rider bounce more than 2 meters off the ground by using elastic bands to store energy. When the pogo’s plunger hits the ground, the elastic bands stretch as the pogo and rider come to rest. At the low point of the bounce, the stretched bands start to contract, pushing out the plunger and launching the rider into the air. For a total mass of 80 kg (rider plus pogo), a stretch of 0.40 m launches a rider 2.0 m above the starting point.

Riders can use fewer elastic bands, reducing the effective spring constant of the pogo. The maximum stretch of the bands is still 0.40 m. Reducing the number of bands will

A. Reduce the force on the rider and give a lower jump height.

B. Not change the force on the rider but give a lower jump height.

C. Reduce the force on the rider but give the same jump height.

D. Make no difference lo the force on the rider or the jump height.