Question

A stone is tied to a weightless string and revolved in a vertical circle of radius 5 m . What should be the minimum speed of the stone at the highest point of the circle so that the string does not slack ? What should be the speed of the stone at the lowest point of vertical circle ? Take ` g = 9.8 ms^(2) ` .

Answer 1

Here, ` r = 5 m , upsilon_(H) = ? `
` upsilon_(L) = ? G = 9.8 m//s^(2) `
The string will not slack at the highest point
when ` upsilon_(H) = sqrt(gr )= sqrt(9.8 xx 5 ) = sqrt( 49) = 7 m//s `
In that case ,
` upsilon_(L) = sqrt(5 gr )= sqrt( 5) sqrtgr = 7 sqrt(5) m // s ` .