A bullet of mass 10 g is fired horizontally 1000 m/s from a rifle situated at a height 50 m  above the ground. If the bullet reaches the ground with velocity 500 m/s the work done against air resistance in the trajectory of the bullet in joule is `(g = 10 m/s^(-2))`

Options

A. 5005 j
B. 3755 j
C. 3750 j
D. 17.5 j

Answer

B

Explanation

`v^(2) =u^(2) -=2as`
`s=-[(v^(2)-u^(2))/(2a)]=(u^(2)-v^(2))/(2a)=(1000^(2)-500^(2))/2a=(375000)/(a)`
Work done opposing resistance of air =` Fs=maxxs`
maxx`(375000)/(a)=(10)/(1000)xx375000=3750J`