Download the app

Questions  

A person of mass 70 kg jumps from a stationary helicopter with the parachute open. As he falls through 50 m height, he gains a speed of 20 ms-1. The work done by the viscous air drag is

a
21000 J
b
-21000 J
c
-14000 J
d
14000 J

detailed solution

Correct option is B

From work-energy theorem, net work done by all forces (internal and external) = change in kinetic energy. ⇒ Work done by gravity + work done by air drag=12×70(202−02) ⇒Work done by air drag =14000 - 35000 = -21000 J

Talk to our academic expert!

+91

Are you a Sri Chaitanya student?


Similar Questions

The work done in moving a body of mass 4 kg with uniform velocity of 5 ms-1 for 10 seconds on a surface of μ = 0.4 is (take g = 9.8 m/s2 )


phone icon
whats app icon