Question

In a rocket of mass 1000 kg fuel is consumed at a rate of 40 kg/s. The velocity of the gases ejected from the rocket is $5\times {10}^{4}m/s.$ the thrust on the rocket is.

• A. $2\times {10}^{3}N.$
• B. $2.5m/s^2.$
• C. $2\times {10}^{6}N.$
• D. $2\times {10}^{9}N.$

Answer 1

The correct option is C $2\times {10}^{6}N.$

Thrust is a reaction force. When a system accelerates a mass in a particular direction, the accelerated mass will cause a force of equal magnitude and opposite direction on that system. Thrust is defined as,

$F_{thrust}=u\frac{dm}{dt}$

$=(5\times {10}^4)\left(40\right)$

$=2\times {10}^{6}N$