Answer:
6.74 s
-39.27 m/s
Step-by-step explanation:
Given:
Δy = -42 m
v₀ = -26.82 m/s
a = -9.8 m/s²
Find: t and v
Δy = v₀ t + ½ at²
-42 m = (-26.82 m/s) t + ½ (-9.8 m/s²) t²
-42 = -26.82t − 4.9t²
4.9t² + 26.82t − 42 = 0
t = [ -26.82 ± √(26.82² − 4(4.9)(-42)) ] / 2(4.9)
t = (26.82 ± 39.27) / 9.8
t = 6.74 s
v² = v₀² + 2aΔy
v² = (-26.82 m/s)² + 2 (-9.8 m/s²) (-42 m)
v = -39.27 m/s