Subject :NSO Class : Class 9
After jumping out from the plane, a parachutist falls 80 m without friction. When he opens up the parachute, he decelerates at 2 m s-2. He reaches the ground with a speed of 4 m s-1. How long did the parachutist spend his time in the air? (Take g = 10 m s-2)
A 4 s
B 16 s
C 18 s
D 22 s