AL phy problem

In an amusement park ride, a person pf mass 63kg rotates in a vertical circle of radius 6.6m.The time taken for one revolution is 3.2s.Find the force which is exerted by the structure on the rider when the rider is at the bottom of the circle

圖片參考：http://hk.geocities.com/namsm4e/P0237.jpg

人的向心力 = F – mg
轉速是ω = 2π / T = 2π / 3.2 = 1.96 rad s-1
所以
F – mg = mω2r
F = mg + mω2r
F = 63x10 + 63 x 1.962 x 6.6
F = 2227N