An aeroplane moving horizontally with a speed of `720 km//h` drops a food pocket, while flying at a height of 396.9 m . the time taken by a food pocket to reach the ground and its horizontal range is (Take `g = 9.8 m//sec`)

Options

A. 3s and 2000m
B. 5s and 500 m
C. 8s and 1500m
D. 9s and 1800 m

Answer

D

Explanation

`t = sqrt((2h)/(g)) = sqrt((2 xx 396.9)/(9.8)) ~~ 9s`
and `u = 720 km//h = 200 m//s`
`:. R = u xx t = 200 xx 9 = 1800 m`