N76/i/1

[Kodomut]

Need help with an ancient A lvl question. Just cant visualise the whole process even though I drew out the diagram

A space research Rocket stands vertically on its launching-pad. Prior to ignition, gas is ejected from the rocker at a speed of 2.5x10^3 ms^-1 relative to the rocket, and fuel is consumed at a constand rate of 7.4kgs^-1. Find the thrust of the rocket and hence explain why there is an interval between ignition and lift-off

g = 10ms-2


I have totally no idea how to find the thrust. =(

[remcook]

there's not much one can do with two numbers. Try some dimensional analysis to see if it fits.

But regardless...you can already have an idea about the second question. Take a guess.

[remcook]

BTW: a force is a change of momentum (the derivative)