A car of mass 1500 kg is moving towards east and its velocity time graph. Class 9

A car of mass 1500 kg is moving towards east and its velocity time graph. Class 9

Question 1.

A car of mass 1500 kg is moving towards east and its velocity time graph is shown below. Calculate the force acting on car during: Class 9

(i) 0 to 5 E,

(ii) 5 to 10s,

(iii) 10 to 15 s.

Answer:

(i) During 0 to 5 s, u = 0 , v = 10 m/s, t = 5 s

v = u + at

10 = 5 a

a = 2 m/s²

F = ma

= 1500 × 2 = 3000 N toward east

(ii) During 5 to 10 s, velocity time graph is straight line parallel to time axis. This means car is moving with constant velocity. Hence no net force is acting on the car.

(iii) During 10 to 15 s, u = 10 m/s, v = 0 m/s, t = 5 s

v = u + at

0 = 10 +5 a

a = -2 m/s²

F = ma

= 1500 × (-2) = -3000 N

Negative sign tells that force is acting in direction opposite to the direction of motion i.e. toward west