Question

A motor car of mass 250 kg is moving with a certain velocity. It is brought to rest by the application of brakes, within a distance of 18 m when the average resistance being offered to it is 1000 N. What was the velocity of the motor car ?

Answer 1

Answer:

Explanation: m = 200 kg

s = 20 m

F = - 500 N

Final velocity v = 0

Initial velocity u = ?

Acceleration = F/m = -500 N/200 kg = -2.5 m/s2.

We have v2-u2 = 2as

u2 = v2-2as

    = 0 -2(-2.5)x 20 m2/s2

    = 100 m2/s2.

u = 10 m/s

Answer 2

Explanation:

stopping distance concept

hope this is the answer