Question

A firework is fired from the ground straight up on a planet with an acceleration due to gravity of 10.56 m/s/s. The firework will not explode until the moment where it would have started to move back down again. The initial speed of the firework is 90.1 m/s. Use this information to find the height at which the firework explodes and the time it will be traveling upward.

Answer 1

384 m

8.53 m/s

Step-by-step explanation:

Given:

v₀ = 90.1 m/s

v = 0 m/s

a = -10.56 m/s²

Find: Δy and t

v² = v₀² + 2aΔy

(0 m/s)² = (90.1 m/s)² + 2 (-10.56 m/s²) Δy

Δy = 384 m

v = at + v₀

0 m/s = (-10.56 m/s²) t + 90.1 m/s

t = 8.53 s