Answer:
Velocity is upward, acceleration is downward
Explanation:
The tennis ball is moving upwards. The direction of the velocity corresponds to the direction of motion of the ball: therefore, it is upward in the first half of the motion of the ball, when the ball is moving upward (while it will be downward after the ball has reached its maximum height, since the ball will start moving downwards).
Instead, the direction of the acceleration is constant. In fact, there is only one force acting on the ball: the force of gravity. Therefore, the acceleration on the ball is equal to
[tex]a=\frac{F}{m}=\frac{mg}{m}=g[/tex]
where (mg) is the force of gravity, m is the mass of the ball, and g is the acceleration of gravity ([tex]g=9.8 m/s^2[/tex]), which acts downward. Therefore, the acceeleration acting on the ball is constant during the whole motion, and therefore it is always acting downward.
