Motion in a Plane

© examsnet.com
Question : 17
Total: 32
A stone tied to the end of a string 80 cm long is whirled in a horizontal circle with a constant speed. If the stone make 14 revolutions in 25 s, what is the magnitude and direction of the acceleration of the stone?
Solution:  
Here, r=80cm=0.8m;υ=
14
25
s1

ω=2πυ=2×
22
7
×
14
25
=
88
25
rad
s1

The centripetal acceleration, a=ω2r=(
88
25
)
2
×0.80
=9.90ms2

The direction of centripetal acceleration is along the string directed towards the centre of circular path.
© examsnet.com
Go to Question: