# Uh Hi help me please?

1. Oct 9, 2008

### chrishere?

1. The problem statement, all variables and given/known data
A jet engine gets it thrust by taking in air, heating and compressing it, and then ejecting it at a high speed. IF a particular engine takes in 20 k/g of air per second at 100 m/s and ejects it at 500 m/s calculate the thrust of the engine.
chriss #getmoney: thrust of the engine would be v right?

2. Relevant equations

i believe that the equation is Mv1 + Mv2 = V(Mv1+Mv2) and that the thrust = V .

3. The attempt at a solution

2. Oct 11, 2008

### Hootenanny

Staff Emeritus
Thrust is a force rather than velocity.

Hint: Try using Newton's Second Law.

Edit: The equation that you have written doesn't make sense, it simplifies to V=1 for all M and v.

Last edited: Oct 11, 2008
3. Oct 11, 2008

### tiny-tim

Welcome to PF!

Hi chrishere?! Welcome to PF!

Thrust is a force, so use Newton's second law in the form force = rate of change of momentum.

How much momentum is being ejected?