Question

A child is standing in the middle of the road when
a driver of a scooter moving with velocity
10 ms-' sees him. He applies brakes to save the
child and brings his scooter to rest in 4s. Calculate
the retarding force on the scooter. Given, mass of
scooter is 300 kg and that of a driver is 60 kg.​

Answer 1

360 kg can be the answer

Explanation:

because i add the weight of the scooter and the person

is it correct

Answer 2

Answer: 900N

Explanation:

Given,

u= 10m/s

v= 0

t= 4s

m= 300+60= 360kg

Now, by 1st equation of motion,

v= u+ at

=>a= v-u/t

=>a= 0-10/4

= -10/4

= -2.5m/s^2

Clearly, the scooter retarded as acceleration is negative.

We know,

F= m × a

= 360 × (-2.5)

= -900 N

Clearly, the force is retarding force as force is negative.

Hence the retarding force is 900N.

Hope this helps you....