# Major Help Required

1. May 19, 2006

### Chazzer3

Question on Kinetic and potentail energy!

I need some major help on the physics question below. I need help quit quickly. I'm sorry if this thread is in the wrong section, but i don't think i have ever seen anything like this before. This is the question:

The Speed of the rocket shown, of mass 20 000kg, has to be increased by 5.0 m/s Squared. If it burns 10kg of fuel and oxygen in doing this, what is the speed of the exhaust gases produced?

The diagram of the rocket is irrelivent

I need someone to please explain how to work it out? I just can't figure it out.

Thanks

Last edited: May 19, 2006
2. May 19, 2006

### StatusX

"has to be increased by 5.0 m/s Squared"

What does this mean?

3. May 19, 2006

### Staff: Mentor

Yeah, speed can't be increased by 5m/s^2. Maybe 5m/s? Or is the acceleration 5m/s^s for some amount of time delta-t?

4. May 19, 2006

### Quaoar

If it's 5 m/s, it's just conservation of momentum:

20,000 kg * (5 m/s) = 10 kg * v

So v = 20,000 / 10 * 5 m/s = 10,000 m/s.

5. May 20, 2006

### willydavidjr

From the given above, I agree that we need to use the equation in conservation of momentum.