A car , moving with a speed of `50 km//hr` , can be stopped by brakes after at least ` 6m `. If the same car is moving at a speed of `100 km//hr`, the minimum stopping distance is

Options

A. `12 m`
B. `18 m`
C. `24 m`
D. `6 m`

Answer

C

Explanation

`v^(2) = u^(2) +2as`
`0 = (50 xx 5//18)^(2) +2a xx 6`
`{:(a=-16m//s^(2),,,(a=retardation),):}`
{:(`:."Again",,,v^(2)u^(2)+2as,):}`
`0 = (100 xx 5//18^(2)) - 16 xx 2xx s`
`S = (100 xx 5)^(2)`
`S = ((100xx5)^(2))/(18 xx 18 xx 32) = 24.1 = 24 m`