Question

A scooter is moving with an initial velocity if 90km/hr and it takes 10s to stop it after the brakes are applied. Calculate the force exerted by the brakes on the scooter if its mass along with the rider is 200kg.

Answer 1

u = 90 m/s = 25 m/s
v =0
t = 10 sec

from 1st equation,
v= u+at
⇒0 = 25 + 10a
⇒10a = -25
⇒a = -2.5 m/s²

Force = ma
          =200×(-2.5)
          = -500 N
Negative shows the direction of force is opposite to the motion.