To answer this question, we convert first the given height and velocity to SI units so we could more comfortably use the equation. The conversion factor to be used is 1 m = 3.28 ft
Height = 4.7 ft x (1 m/ 3.28 ft) = 1.43 m
Velocity = 25 ft / s x (1 m / 3.28 ft) = 7.62 m/s
The maximum height that can be attained by an object following a projectile path is calculated through the equation,
H = (v₀²)(sin²θ) / 2g
where v₀ is the initial velocity, H is the maximum height and g is the acceleration due to gravity.
Transforming the equation to calculate for θ,
sinθ = sqrt ((H)(2g) /(v₀²))
sinθ = sqrt ((1.43)(2)(9.8)) / (7.62²))
sinθ = 0.76
We calculate for the angle by getting the arcsin.
sin⁻¹ (0.76) = 49.46°
ANSWER: 49.46°