Question

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

Answer 1

u = 90 m/s = 25 m/s
v = 0
t = 10 sec
as, v = u +at
⇒0 = 25 + 10a
⇒10a = -25
⇒a = -2.5 m/s²
Force = mass×acceleration
          =200×(-2.5)
          = - 500 N
negative shows the direction of force is opp. to the direction of motion.

if mass is halved, F = 100×(-2.5) = -250 N

Answer 2

Answer:

Explanation:

Given :-

u = 90 m/s = 25 m/s

v = 0

t = 10 sec

To Find :-

Force

Formula to be used :-

v = u +at

Force = Mass × Acceleration

Solution :-

Putting all the values, we get

v = u +at

⇒ 0 = 25 + 10a

⇒ 10a = -25

⇒ a = -2.5 m/s²

Force = Mass × Acceleration

Force = 200×(-2.5)

Force = - 500 N

Negative shows force is acting opp. to the direction of motion.

Mass is halved, F = 100 × (-2.5) = -250 N

Hence,  the force if the mass is halved as -250 N.