# Find rocket thrust, inteval between ignition and lift-off

Please provide a detailed solution to the following problem:

A rocket stands vertically on a launching pad, the mass of the fuel and the rocket is 1.9*10^3 kg. On ignition, gas is ejected from the rocket at a speed of 2.5*10^3 m/s relative to the rocket, and fuel is consumed at a constant rate of 7.4 kg/s. Find the thrust of the rocket and hence explain why there is an interval between ignition and lift-off. (take g=10 m/s^2).

Â© BrainMass Inc. brainmass.com March 4, 2021, 9:58 pm ad1c9bdddfhttps://brainmass.com/physics/newtons-second-law/rocket-thrust-inteval-between-ignition-lift-off-287687

#### Solution Preview

A rocket stands vertically on a launching pad, the mass of the fuel and the rocket is 1.9x103 kg. On ignition, gas is ejected from the rocket at a speed of 2.5x103 m/s relative to the rocket and fuel is consumed at a constant rate of 7.4 kg/s. Find the thrust of the rocket and hence explain why there is an interval between ignition and lift-off. (take g=10 m/s^2).

Solution:

...

#### Solution Summary

The expert finds the rocket thrust and the interval between ignition and lift-off.