Question

A car is moving with the speed of 10m s .when the brakes are applied the car has constant negetive acceleration of2m s*s .what is its stopping distance.

Answer 1

initial velocity=u=10m/s*

final velocity=v=0(as car comes to rest)

negative acceleration= -2m/s*s
 
distance travelled=?

by using second equation of motion:

v*v=u*u+2as

0=10*10+2*(-2)*s

0=100-4s

4s=100

s=100/4

s=25

so distance travelled during brakes applied = 25m

*note=we have taken intial velocity=constant speed because speed is used in terms of velocity in regular use