Third Law of Motion Problem Finding average Force

[twisted]

1. A 9800kg rocket is traveling east along a horizontal frictionless rail at a velocity of 11m/s. The rocket is then accelerated uniformly to a velocity of 22m/s in a time of 0.75s by the expulsion of hot gases. What is the average force at which the gases are expelled by the rocket?

Homework Equations

3.
Finding the net acceleration.
22 = 11+a(0.75)
18.333=a
Finding force.
F = 9800x18.33
F = 179634

What have I done wrong here?

 

[Delphi51]

Welcome to PF, Twisted!
My calculator says 14.67 for that
22 = 11+a(0.75)
11 = .75*a subtracted 11 from both sides
a = 11/.75 = 14.67 divided both sides by .75

 

[twisted]

Ugh, I can't believe I entered it into my calculator wrong. I got it right now. Thanks a lot for the quick response!