A mass of 5 kg is tied to a string of length 1.0 m is rotated in vertical circle with a uniform speed of `4 m//s` . The tension in the string will be 170 N when the mass is at `(g=10 m//s^(2))`

Options

A. highest point
B. mid way
C. bottom
D. cannot be justified

Answer

B

Explanation

`T=(mv^(2))/(r)+mg cos theta`
`therefore mg cos theta =T-(mv^(2))/(r)`
`=170-(5xx16)/(1)=170-80`
`cos theta = (90)/(5xx10)=(9)/(5)`
Can not be predicate .