Question

18. The velocity time graph of a ball of mass to kg moving along a straight line on table is given below: 1 mark) Velocity lem/s) 5 . 10 11 What is the force exerted by the table on the ball to make it stop? In questions 19 and 20, a statement of assertion (A) is followed by a statement of reason (R). Choose your answer as if both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A). (m) both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A). (I) assertion (A) is true but reason (R) is false, (iv) assertion (A) is false but reason (R) is true.​

Answer 1

Answer:

Mass of the body, m=20 g=0.02 kg

From the given graph, we note that

Initial velocity, u=20 m/s=20 m/s

Final velocity, v=0 m/s

Time taken, t=10−0=10s

The force exerted on the ball is,

F=m x a

F=m x (v−u)/t

F=−0.04 N

The negative sign shows that the friction force exerted by the table is opposite to the direction of motion of the ball