A player throwsa a ball upwards with an initial speed of `29.4 ms^(-1)`.
(i) What is the direction of acceleration during the upwared motion of the ball?
(ii) What are the velocity and acceleration of the ball at the highest point of its motion?
(iii) Choose the x=0 and t=0 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 positive, velocity and acceleration of the ball during its upward, and downward motion.
(iv) To what height does the ball rise and after how long does the ball return to the player's hand?( Take g`=9.8 ms^(-2)`, and neglect air resistance).

Explanation

(a) Acceleration is directed downwards
(b) At highest point v =0, a = g (downwards)
(c ) For upward motion (Reference point to be the highest point)
`" "{:(x to "Positive"),(v to "negative"),(a to "positive"):}`
For downward motion
`" "{:(x to "Positive"),(v to "Positive"),(a to "Positive"):}`
(d) `H = (v^(2))/(2g) = 44.1 m, T = (2v)/(g) = 6 sec`.