A rocket, set for vertical launching, has a mass of 50 kg and contains 450 kg of fuel. It can have a maximum exhaust speed of `1 kms^(-1)` If `g = 10 ms^(-2)`. What should be the minimum rate of fuel consumption to just lift it off the launching pad ?

Options

A. `10 kg s^(-1)`
B. `5 kg s^(-1)`
C. `7.5 kg s^(-1)`
D. `2.5 kg s^(-1)`

Answer

b

Explanation

Here Thrust `F=u(dm)/(dt)`
to lift the rocket `F=Mg`
`:.Mg=u(dm)/(dt)implies(dm)/(dt)=(500xx10)/(1000)=5kg s^(-1)`
Hence correct choice is (b)