A small test rocket of initial mass is at rest on a horizontal frictionless track
PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A small test rocket of initial mass 25kg is at rest on a horizontal frictionless track. It ejects 5.0kg of burnt gases in 0.10s at a constant speed of 400ms−1 relative to the rocket.
(i) Calculate the speed of the rocket immediately after the gas has been completely expelled.
(ii) Determine the magnitude of the average force experienced by the rocket during the ejection of the gases.
(iii) Briefly explain, with reference to Newton’s laws, how the rocket is able to accelerate in the absence of any external horizontal force.