A bus was moving with a speed of `54 km//h`. On applying brakes , it stopped in 8 seconds . Calculate the acceleration and the distance travelled before stopping.

Answer

`-1.87 m//s^(2)` ; `60.2 m`

Explanation

Here , `u = 54 km//h = ( 54 xx 1000 m)/( 60 xx 60 s) = 15 m//s, v = 0 , t = 8 s, a = ? , s= ?`
From ` v = u + at` , `a = ( v - u) /(t) = ( 0 -15) /(8) = - 1.87 m//s^(2)`
From ` s = u + (1)/(2) at^(2)` , `s = 15 xx 8 + (1)/(2) ( - 1.87)(8)^(2) = 60.2 m`