A rocket of mass 1000 kg is to be projected vertically upwards. The gases are exhausted vertically downwards with velocity `100m//s` with respect to the rocket. (What is the minimum rate of burning fuel, so as to just lift the rocket upwards against the gravitational attraction?) (Take `g=10m//s^(2)`)

Options

A. 50 kg/s
B. 100kg/s
C. 200kg/s
D. 400kg/s

Answer

B

Explanation

Minimum rate of burning fuel is `(dm)/(dt)`
`therefore mg=u(dm)/(dt)`
or, `(dm)/(dt)=(mg)/(u)=(1000xx10)/(100)=100 kg/s`.