Question

On turning a corner, a motorist rushing at `44ms^(-1)` finds a child on the road `100 m` away. He applies the brakes so as to stop the motorcar within `1 m` of the child. Calculate the time required to stop.

Answer 1

` u= 44 ms^(-1) S= 100 - 1 =99 m, `
v= 0 , t= ?
` a = ( u^2 -u^2) /( 2 s) = ( 0- ( 44) ^2 /(2 xx 99 ) = (-88) /9 m//s^(-2)`
` t= ( v-u)/a = ( -044)/(-88 //9) = 9/ 2 = 4.5 s` .