Question

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

Answer 1

Hi friend
The velocity of the ball changes four times.
1 when the player kicks the ball at rest to another player (agent supplying force is the first player)
2. when the other player kicks the ball towards thebgoal (ageny supplying the force is second player)
3. third time when the goal keeper of the opposite team collects it (agent applying force is the goal keeper)
4. fourth time when the goal keeperbkocks the ball towards the player of his own team . ( agent supplying force is again the goal keeper.)

thanks hope thos helps ...........

Answer 2

(i)Velocity of the football changes when first player kicks the ball towards another player of his team. (ii) Velocity of the football also changes when another player kicks the football towards the goal. (iii) Velocity of the football also changes when the goalkeeper of the opposite team stops the football by collecting it. (iv) Velocity of the football changes when the goalkeeper kicks it towards a player of his team. Thus, the velocity of the ball changes four times in this case. In first and second cases, the force is supplied by the foot of players. In third case, force is supplied by the hands of the goalkeeper. In fourth case, as the goalkeeper hits the football with his foot, so the foot of the goalkeeper supplies the force.