A skydiver jumps from an airplane at an altitude of 2,500 ft. He falls under the force of gravity until he opens his parachute at an altitude of 1,000 ft. Using the initial velocity of zero, approximately how long does the jumper fall before he opens his chute?For this quadratic model we will let the y-axis be the axis of symmetry.h(t) = -16t2 + vt + h0
The jumper falls 2,500 − 1,000 = 1,500 ft before opening the parachute. With initial velocity zero, the model gives 1,500 = 16t², so t = √(1,500/16) ≈ 9.7 seconds; the correct choice is 9.7 s.
AI-written and checked against the verified answer.