Question

An airplane pilot jumps out of an airplane and has an initial velocity of 32 feet per second downwards. How long does it take to fall from 1000 feet to 760 feet before the parachute opens?

Answer 1

Answer:

3 seconds

Step-by-step explanation:

Downwards positive

a = 32

s = 1000 - 760 = 240

s = ut + ½at²

240 = 32t + 16t²

t² + 2t - 15 = 0

t² + 5t - 3t - 15 = 0

t(t + 5) - 3(t + 5) = 0

(t - 3)(t + 5) = 0

t = 3, -5