Answer:
The height of the building is 88.63 m.
Explanation:
Given;
initial component of vertical velocity,
= 12 m/s sin 26° = 5.26 m/s
initial horizontal component of the velocity,
= 12 m/s cos 26° =10.786 m/s
horizontal distance traveled by the rock, x = 40.4 m
time of flight is calculated as;
x =
t
t = x / 
t = 40.4 / 10.786
t = 3.75 s
Determine the final vertical velocity of the ball;

Determine the height of the rock;

Therefore, the height of the building is 88.63 m.