Explanation:
Given:
v₀ = 25 m/s
v = 0 m/s
a = -9.8 m/s²
1a) Find t.
v = at + v₀
0 m/s = (-9.8 m/s²) t + 25 m/s
t = 2.55 s
1b) Find Δy.
v² = v₀² + 2aΔy
(0 m/s)² = (25 m/s)² + 2 (-9.8 m/s²) Δy
Δy = 31.9 m