Question

A football of mass 0.5 kg coming towards player with a velocity of 10 m/s. Player hit straight back the football with velocity 15 m/s. If the contact time is 0.02 second then the average force involved is: - (1) 250 N (2) 1250 N (3) 500 N (4) 625 N​

Answer 1

Average force involved is a retarding force of 625 N

Explanation :-

we have :-

→ Mass of the football (m) = 0.5 kg

→ initial velocity (u) = 10 m/s

→ Final velocity (v) = 15 m/s

→ contact time (t) = 0.02 sec

______________________________

we can understand that initially the football was moving in onr direction, and the play hit it back to the direction. so, its final velocity will be -15 m/s

Now just calculate the average force by Newton's 2nd law of Motion.

F = m(v-u)/t

• F = 0.5(-15 - 10)/0.02
• F = 0.5(-25)/0.02
• F = 12.5/0.02
• F = -12.5/0.02
• F = -1250/2
• F = -625 N

Here, - ve sign represents retarding Force