Given that a football is kicked into the air vertically upwards, let's determine the following:
(a) Velocity at the highest point.
As the ball is kicked vertically up, it has an initial velocity.
As the ball moves up, the velocity decreases because of the force of gravity acting on it.
When the ball reaches the highest point, the velocity of the ball will be zero.
Therefore, the velocity of the ball at the highest point is zero.
(b) Acceleration at the highest point.
The acceleration of the ball as it is kicked up is equal to the acceleration due to gravity.
Where:
Acceleration due to gravity, g = 9.8 m/s².
Since the ball is moving upwards, the acceleration due to gravity is acting vertically downwards which makes the acceleration of the ball constant.
The acceleration of the football at the highest point is the opposite of acceleration due to gravity = -9.8 m/s².
ANSWER:
• a) Velocity at the highest point is 0.
,
• b) Acceleration at the highest point is -9.8 m/s².