Question

In the following example, try to identify the number of times the velocity of the ball changes: "A football player kicks a football to another player of his team who kicks the football towards the goal. The goalkeeper of the opposite team collects the football and kicks it towards a player of his own team". Also identify the agent supplying the force in each case.

Answer 1

The rate of change of an object's position with respect to a frame of reference is called velocity, and it is a function of time. Velocity is a physical vector quantity that requires both magnitude and direction to define.

Complete step by step answer:
Football's velocity changes four times.
When a football player kicks the ball to another player, and then kicks the ball to the goalkeeper. The third time the ball is stopped by the goalkeeper. When a goalkeeper kicks the ball towards a player on his own team, it is the fourth time the velocity changes.
How does the ball's velocity change?
The ball's velocity changes in the following way:
(i) The speed of the football changes from zero to a certain value when the first player kicks it. At that point, the ball's velocity was zero because it was at rest.
(ii) The ball's direction is changed when another player kicks it towards the goal post. The ball's velocity changes as the direction changes. As a result, its velocity changes.
(iii) When the goalkeeper collects the ball, the ball's speed decreases from a certain value to zero. As the ball comes to a complete stop, the velocity drops to zero. The ball's velocity has changed yet again.
(iv) The goalkeeper kicks the ball in the direction of his teammates. As a result, the ball's speed increases from zero to a specific value. As a result, its velocity increases to a certain point and then changes.
Agent in charge of supplying the force:
a) The first case is that of the first player.
b) The second case is that of the second player.
c) Goalkeeper is the third case.
d) Goalkeeper is the fourth case.

Note: A force is an external agent capable of altering a body's state of rest or motion. There is a magnitude and a direction to it. The force's direction is known as the force's direction, and the point where force is applied is known as the point where force is applied.