Question

The driver of a three wheeler moving with
a velocity of 40 kmh 1 sees a child
Standing in the middle of the road and brings
his vehicle to rest in 5 seconds
time to save the child - What is the
average retarding force on the vehicle. The
mass of the three wheeler is 500kg and
the mass of the driver is 70kg​

Answer 1

Answer:

ANSWER

Given:

Initial speed of the three-wheeler, u=36km/h=10m/s

Final speed of the three-wheeler, v=0 m/s

Time, t=4s

Mass of the three-wheeler, m=400 kg

Mass of the driver, m

′

=65kg

Total mass of the system, M=400+65=465 kg

Using the first law of motion, the acceleration (a) of the three-wheeler can be calculated as:

v=u+at

a=

t

(v−u)

=

4

(0−10)

=−2.5m/s

2

The negative sign indicates that the velocity of the three-wheeler is decreasing with time.

Using Newton's second law of motion, the net force acting on the three-wheeler can be calculated as:

F=Ma=465×(−2.5)=−1162.5N

The negative sign indicates that the force is acting against the direction of motion of the three-wheeler.