Answer to Question #278774 in Physics for john

Question

a circus man whose mass is 60 kg is standing on a platform 20 m above the ground while holding a trapeze which is 10 m long that is attached to the ceiling which is 26 m above the ground. the circus man swings and let go of the upswing. determine the potential energy relative to the ground if each of the following position of the circus man:

a. 20 m on the platform

b. 16 m at the bottom of the swing

c. 18 m and let's go out the trapeze

d. 9 meters halfway to the ground

Answer 1

a. 20 m on the platform:

$$E=mgh=60·9.8·20=11760\text{ J}.$$

b. 16 m at the bottom of the swing:

$$E=mgh=60·9.8·16=9408\text{ J}.$$

c. 18 m and let's go out the trapeze:

$$E=mgh=60·9.8·18=2822\text{ J}.$$

d. 9 meters halfway to the ground:

$$E=mgh=60·9.8·9=1411\text{ J}.$$