Question

A car moving with velocity 54 kilometre per hour on a straight road stops on applying brakes after covering a distance of 20 m compute the acceleration of the car

Answer 1

so given stopping distance of car i.e.20m

given initial velocity of car i.e. 54km/hr=15m/s

so to find acceleration

formula=v^2-u^2=2as

here v final velocity is zero.

so acceleration a=-u^2/2s

so a= -5.625m/sec^2