Answer:
Explanation:
initial speed, u = 19 m/s 
(a) Let it rises upto height h. 
Use third equation of motion
v² = u² - 2 gh 
where, v is the final velocity and it is zero. 
0 = 19 x 19 - 2 x 9.8 x h 
h = 18.4 m 
(c) Let the ball takes time t to reach to the maximum height. 
use first equation of motion 
v = u - gt 
0 = 19 - 9.8 x t 
t = 1.94 s
(c) The time taken by the ball to reach to the ground = 2 x time to reach to maximum height 
T = 2 x t = 2 x 1.94 = 3.88 s 
(d) When the ball reaches the ground, let the velocity is v. 
Use third equation of motion 
v² = u² - 2 gh 
where, v is the final velocity
v² = 0 + 2 x 9.8 x 18.4 
v = 19 m/s