Answer:
(a) 31.25 m
(b) 5 second
(c) 25 m/s
Explanation:
u = 25 m/s , g = 10 m/s^2
(a) Let the ball rises upto height h
use third equation of motion
v^2 = u^2 - 2 g h
The final velocity v is zero at maximum height
0 = 25^2 - 2 x 10 x h
625/20 = h
h = 31.25 m
(b) Let it reaches to maximum height in time t
use first equation of motion
v = u - g t
0 = 25 - 10 x t
t = 2.5 s
It takes T time to reach the ground.
T = 2 t = 2 x 2.5 = 5 s
(c) Let it reaches the ground with velocity v
Use third equation of motion
v^2 = u^2 + 2 g h
v^2 = 0 + 2 x 10 x 31.25
v = 25 m/s
