Copyright © Michael Richmond.
This work is licensed under a Creative Commons License.

##
Physics 211, Quiz 16

Question 1:
Joe has a mass **m = 60 kg**.
He enters "The Cyclone," a carnival ride
in which a cylindrical room of diameter **D = 6 m**
spins around its axis.
Joe stands against the wall as the room stars to spin.
It speeds up until it makes one revolution in **T = 2 sec**.
Joe feels the wall pressing against his back.
How strong is this normal force?

Answer: The normal force provides the push to keep Joe moving in
uniform circular motion. It thus provides the centripetal
force
m v^2
F = ------
R
Here, room has radius R = 3 m, and circumference
C = 2 pi R = 18.8 meters. The room makes on revolution
in T = 2 seconds, and Joe spins with speed
C 18.8 m
v = ----- = ------ = 9.4 m/s
T 2 s
Therefore, the centripetal force is
m v^2 (60 kg) * (9.4 m/s)^2
F = ------ = -----------------------
R 3 m
= 1770 N

Copyright © Michael Richmond.
This work is licensed under a Creative Commons License.