Question

A rocket is going upwards with accelerated motion. A man sitting in it feels his weight increased 5 times his own weight. If the mass of the rocket including that of the man is $1.0\times {10}^{4}kg$, how much force is being applied by rocket engine?

• A. $5\times {10}^{4}N$
• B. $5\times {10}^{5}N$
• C. $5\times {10}^{8}N$
• D. $2\times {10}^{4}N$

Answer 1

The correct option is B $5\times {10}^{5}N$

Given , Total mass(man+rocket), $m^{\prime }=1.0\times {10}^{4}kg$

the mass of man sitting in the rocket is increased by 5 times.

As force due to mass $=$mg,

So, $a=5g=5\times 10=50m/s^2$.

Force applied by the rocket engine,

$F=ma=1.0\times {10}^4\times 50=5\times {10}^{5}N$