Question

a scooter moving with a speed of 36 km per hour sees a child standing in the middle of the road he applies the brakes and brings the scooter to rest in 5 sec just in time to save child calculate the average retarding force on the vichle if mass of the vichle and driver is 300 kg

Answer 1

Here,

U= 36 km/ hr

When changed to m/ sec it is

36 x 5/18

= 2 x5

=10 m/sec.

V= 0

T= 5 sec.

According to the formula,

A= (v-u) /t

= (0-10) / 5

= -2m/ sec2.

Thus, retardation= 2/m sec2.

The average retarding force on the vehicle if mass of the vehicle and driver is 300 kg is 600 N.

As, Average retarding force = 300×2 = 600N.

Answer 2

Explanation:

u= 36 km / h

10 m/s

v=0

t= 5s

m= 300kg

a = ?

f = ?

v = u +at

0 = 10+ 5a

-a = 2 m/s²

now

F = Ma

F = 300(-2)

F = -600 N

because negative use to retardation

that's by negative force