Question

A rocket with a lift-off mass $20,000kg$ is blasted upwards with an initial acceleration of $5.0m{s}^{-2}$. Calculate the initial thrust (force) of the blast.

Answer 1

Mass of rocket, $m=20,000kg$

Initial acceleration, $a=5m/s$${}^2$
$g=10m/s$${}^2$
Using Newton's second law of motion, the net force (thrust) acting on the rocket is given as:

$F=mg+ma=m(a+g)=20000(10+5)=20000\times 15=3\times {10}^{5}N$

$F=3\times {10}^{5}N$