Question 268960
Height of ceiling from balcony, h = 58 - 10 = 48 ft.
Upward velocity of the ball while throwing, u = 64 ft/sec.
Acceleration due to gravity, g = 32 ft/sē.


The equation of motion is h = ut - (1/2)gtē.
48 = 64t - (1/2) x 32 x tē
48 = 64t - 16tē
16tē - 64t + 48 = 0
tē - 4t + 3 = 0
(t-3)(t-1) = 0
So either t = 1 or t = 3. 


The answer will be the smaller value of 't' when the ball will hit the ceiling so t = 1.


Ans. The ball will hit the ceiling after 1 second from the time of its throwing.