A body is allowed to fall from a height of  100m. After 2s if acceleration due to gravity vanishes the total time of its fall is g=10 m/s2 in sec

Distance travelled in 2s is h=12gt2                                   =12×10×22=20 mVelocity acquired after 2s is v=gt                                   =10×2=20 m/sAs there is no acceleration, that body could travel the remaining distance 100−20=80 m with uniform velocity of 20m/s.∴ The time taken for the remaining journey is t=8020=4 s.∴ Total time of motion is 2+4=6 s