Answer: height = 60.5 m
Explanation:
given that the
Initial velocity U = 18.5 m/s
Range = 38.9 m
Let us use second equation of motion under gravity
S = Ut + 1/2gt^2
Where S = range R
Since the motion is horizontal, g = 0
The equation is reduced to:
R = Ut
Make t the subject of formula
t = R/U
Substitute range R and U into the formula
t = 38.9/ 18.5
t = 2.1 s
To calculate the vertical height, we will consider g = 9.81 m/s^2 by using the same second equation of motion
h = Ut + 1/2gt^2
Substitute U, t and g into the formula
h = (18.5 × 2.1) + 1/2 × 9.8 × 2.1^2
h = 38.9 + 21.609
h = 60.51 m
The building is 60.51 metres tall.
