Question

(a) While playing football, a player applies force on the ball by kicking it.
(i) Can he change the speed of the ball without changing its direction of motion?
(ii) Can he change the direction of motion of the ball without changing its speed? (iii) Can he change both the direction as well as the speed of motion of the ball? Give, in brief, & the reason for your answer in each case.

Answer 1

yes he can change the speed without changing it's direction by kicking again it in same direction
no he cannot change the direction of motion of the ball without changing it's decision

Answer 2

Answer:

While playing 'football', a "player applies force" on ball by kicking the ball

(i) No, he cannot change the speed of the "ball without changing" its direction of motion.

• "Force acting on a body" will accelerate it or will change the direction of its motion.

(ii) No, he cannot change the motion direction of the ball without changing its speed.

• According to Newton’s Law, a body moves in the force direction applied to it.

• Force applied on a body will change both the direction and speed of the ball.
• The ball will accelerate in the 'same direction' as that of the force applied to it.
• Force acts at a particular direction and when force has applied the speed of the body will also increase.

(iii) Yes, the player can change both the direction and the speed of the motion of the ball by 'applying force on the ball'.

• Force acting on a body will accelerate it or will change the "direction of its motion".