A particle thrown up vertically reaches its highest point in time `t_(1)` and returns to the ground in further time `t_(2)`. The air resistance exerts a constant force on the particle opposite to its direction of motion

Options

A. `t_(1) gt t_(2)`
B. `t_(1) = t_(2)`
C. `t_(1) lt t_(2)`
D. May be (a) or (c ) depending on the ratio of the force of air resistance to the weight of the particle.

Answer

B

Explanation

`N+60 -mg =0`
`N=40`
`f_(s) " max "=mu_(s) N`
`f_(s)" max " = 70`, hence answer is 70 N