Question

For a body of mass 5kg, initially at rest, the force - time graph is as shown, choose the correct statement.

• A. The change in momentum of body is 25 kg-m/s
• B. The velocity of the body at the end of 10 seconds is 25 m/s.
• C. The initial momentum of the body is a non- zero value
• D. All of these

Answer 1

The correct option is A

The change in momentum of body is 25 kg-m/s

From Newton's second law of motion, we have studied that the force acting on a body is directly proportional to the rate of change of momentum. So, the area under the Force-time curve gives the change in momentum due to the force acting on a body for a certain interval. So, area of the right angle triangle would give us the change in momentum which is equal to 1/2 x 10 x 5 = 25 Kg-m/s. Since the initial momentum is zero, therefore final momentum would also be equal to 25 kg-m/s. So, the velocity of the body at the end of 10s would be 25/5 = 5 m/s