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?
A)914 m
B)1 130 m
C)1 520 m
D)1 750 m

Question

Quizplus · Accepted Answer

The correct answer is A.The parachutist accelerates with gravity to a maximum velocity of 58.8 m/s in 6.00 seconds. So, the acceleration due to gravity is:a = (58.8 m/s) / (6.00 s) = 9.80 m/s^2The parachutist 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. So, the deceleration is:a = (10.0 m/s - 58.8 m/s) / (4.00 s) = -12.2 m/s^2The height from which the parachutist jumped is:h = (1/2) * (58.8 m/s + 10.0 m/s) * (60.0 s) = 914 m

A Parachutist Jumps Out of an Airplane and Accelerates with Gravity