Question

A player throws a ball upwards with an initial speed of 29.4 ms^-1.

(a) What is the direction of acceleration during the upward motion of the ball?

(b) what are the velocity and acceleration of the ball at the highest point of its motion?

(c) Choose the x = 0 m and t = 0 s to be the location and time of the ball at its highest point, vertically downward direction to be the positive direction of x - axis, and give the signs of position, velocity and acceleration of the ball during its upward and downward motion,

(d) To what does the ball rise and after how long does the ball return to the player 's hands?

Answer 1

(a) The ball is under the influence of acceleration due to gravity, which always acts vertically downwards.

(b) Velocity at highest point = zero.

Acceleration at highest point = g = 9.8 ms^-2 (↓)

(c) For upward motion:

(i) Position	Negative
(ii) Velocity	Negative
(iii) Acceleration	Positive
For downward motion:
(i) Position	Positive
(ii) Velocity	positive
(iii) Acceleration	Positive

(d) During upward motion:

Total time = 3 +3 = 6 s. [Time of ascent = time of decent)