posted by winterWX on .
A boy whirls a stone in a horizontal circle of radius 1.2 m and at height 2.0 m above ground level. The string breaks, and the stone flies horizontally and strikes the ground after traveling a horizontal distance of 10 m. What is the magnitude of the centripetal acceleration of the stone while in circular motion?
How long did it take to fall to the ground? h= 1/2 g t^2
solve for t.
Then, its velocity is 10m/time
centripetal acceleration then is ...
ok, so I did h=1/2 g t^2 and got t=.64s
Then I did V=10 / .64 = 15.7 m/s
Then I did a=v^2 / r
a = (15.7)^2 / 1.2 = 204.2 ??? that seems way too big. what am I doing wrong??
looks right to me, 204m/s^2, about 20g
ok. thanks for your help!