posted by Sierra .
The track near the top of your favorite roller coaster has a circular shape with a diameter of 36 m. When you are at the top, you feel as if you weigh only one-fifth of your weight on the ground. What is the speed of the roller coaster?
apparent weight= 1/5 mg
but apparent weight= weigh-centripetalforce
1/5 mg= mg-mv^2/r
solve for v