Question

1. A Ferris wheel has a radius of 6 m and makes one revolution in 4seconds (i.e. onerevolution in approximately 12.6 seconds). A person with a mass of 50 kg is sitting on one of thebenches attached to the rim. What is the normal force acting on a the person at the highest pointof the rotating Ferris wheel? Approximate the acceleration due to gravity as 10 m/s2; on a Ferriswheel, the passengers are never upside down.

2. Consider what happens when you jump up in the air. Which of the following is the mostaccurate statement?

A. You are able to spring up because the earth exerts a force upward on you that isgreater than the downward force you exert on the earth.

B. Since the ground is stationary, it cannot exert the upward force necessary to propelyou into the air. Instead, it is the internal forces of your muscles acting on your bodyitself that propels your body into the air.

C. When you push down on the earth with a force greater than your weight, the earth willpush back with the same magnitude force and thus propel you into the air.

D. It is the upward force exerted by the ground that pushes you up, but this force cannotexceed your weight

E. When you jump up the earth exerts a force F1 on you and you exert a force F2 on theearth. You go up because the magnitude of F1 is greater than the magnitude of F2.

3. A ball of mass m is attached to a massless string of length L. Grasping the end of the string, achild whirls the ball first in a horizontal circle and then in a vertical circle (at the same constantspeed in both cases; the ball travels on a frictionless surface for the horizontal circle). The stringtension in the horizontal circle equals the string tension in the vertical circle.

Answer 1