Question

A parachutist jumps out of an airplane and accelerates with gravity to a maximum velocity of 58.8 m/s in 6.00 seconds. She then pulls the parachute cord and after a 4.00‑second constant deceleration, descends at 10.0 m/s for 60.0 seconds, reaching the ground. From what height did the parachutist jump?

Answer 1

Answer:

From what height did the parachutist jump?

914 m

Explanation:

v = 58.8 m/s

u = 0 m/s

a = 9.81 m/s^2

t = 6.00 s

v^2 = u^2 + 2as

58.8^2 = 0 + 19.62s

s = 3457.44/19.62 = 176.22m

Upon decelerating after opening parachute;

v = 10 m/s

u = 58.8 m/s

t = 4.00

deceleration =( 58.8 - 10)/4.00 = 12.2 m/s^2

v^2 = u^2 + 2as

100 = 58.8^2 - 24.4s

3357.44/24.4 = s

s = 137.6s

Upon decending at constant velocity

distance = time*velocity = 10.0*60 = 600 m

Initial height = 600 + 137.6 + 176.22 = 913.82 m = 914 m