Question

In a rocket of mass 1000 kg, fuel is consumed at a rate of $40\,kgs^{-1}$ The velocity of gases ejected from rocket is $5\times10^4\,ms^{-1}$ . The thrust on rocket is

• A. $2\times10^3$N
• B. $5\times10^4$N
• C. $2\times10^6$N
• D. $2\times10^8$N

Answer 1

Answer: (C)

$2\times10^6$N

Answer 2

Thrust is normal force given by. F = $\frac{d}{dt} mu = u \frac{dm}{dt} = (5 \times 10^4)(40)$ $= 2 \times 10^6 \, N$