Question

A rocket engine uses fuel and oxidizer in a reaction that produces gas particles having a velocity of 1380 ms-1. The desired thrust is to be 195000 N.

1-What must be the fuel/oxidizer consumption rate (in kg s-1)?

2-f the initial weight of the rocket is 125000 N, what is its initial acceleration?

3-What are the weight and acceleration of the rocket at t = 15.0 s after ignition?

4-What are the weight and acceleration of the rocket at t = 20.0 s after ignition?

Please help all my classmates doesn't know how to solve this and its due tomorrow *face crying*

Answer 1

force=massfuelrate*velocity
massfuelrate= forcedesired/velocty

Initial,it has to operate against gravity.

Thrust=mg+ma=m(9.8+a)
solve for a. mass=initialweight/9.8

3. figure the mass lost in 15 sec(massrate*time)
then do 2 over with the new weight

3.same thing again.