Answer to Question #80441 in Classical Mechanics for Hanna

Question

A rocket fired straight up with a given velocity travels a certain distance and then it’s engine stops. I have to calculate how much distance it travels further and how much time it stays in air. My question is, after the engine stops, does it’s acceleration become g or -g ?

Answer 1

It’s acceleration become –g. it is because the positive direction is upwards (rocket fired straight up). Thus, the acceleration will be directed downwards and has negative sign.