A 10 kg stone is suspended with a rope of breaking strength 30 kg-wt. The minimum time in which the stone can be raised through a height 10 m starting from rest is (Take, `g = 10 N kg^(-1)`).

Options

A. 0.5 seconds
B. 1.0 seconds
C. `sqrt((2)/(3))` seconds
D. 2.0 seconds

Answer

B

Explanation

m = 10kg , breaking force = 30kg wt = 300 N = `T_("max") T - mg = ma `
`rArr a = (300 - 10xx 10)/(10) = 20 m//s^(2)`
`rArr S = (1)/(2) xx a xx t^(2) rArr 10 = (1)/(2) xx 20 xx t^(2)`
`rArr t = 1 sec`.