Rocket Mass & Accel: 6000kg, 25m/s2

[iamwilson]

Homework Statement

If the rocket has an initial mass of 6000kg and ejects gas at a relative velocity of magnitude 2000m/s , how much gas must it eject in the first second to have an initial acceleration of 25.0m/s^2

Homework Equations

v=v_exln(m_0/m)

The Attempt at a Solution

i tried using momentum to solve the question
6000(2000)=Ft, t=1s, F=12000000, then F=MA,so i 12000000=25m,
m=480000
but it was not correct
then i tried to used the above v equation, but i don't have the v_ex

 

[Snazzy]

You already have a thread on this very same question in this very same sub-forum.