# A Rocket

#### PearlyD

1. The problem statement, all variables and given/known data
A Saturn V rocket has a mass of 2.75x10^6 Kg and exerts a force of 3.3x10^6N on the gases it expels.
determine the initial vertical acceleration of the rocket.

2. The attempt at a solution
heres my attempt...
F=3.3x10^6N
Fg=
M=2.75x10^6
Fnet-MA
F-Fg=ma
F-mg=ma
3.3x10^6-(2.75x10^6)(9.8)=2.75x10^6a
3.3x10^6-2.6x10^7=2.75x10^6a
-2.2x10^7=2.75x10^6a
-2.2x10^7/2.75x10^6=a
a=-8

The accual answer is 2.2m/s^2
Can someone explain to me what i got wrong?

#### ideasrule

Homework Helper
Are you sure it's 3.3x10^6N and not 3.3*10^7 N? You get the correct answer with 3.3*10^7 N.

#### PearlyD

Are you sure it's 3.3x10^6N and not 3.3*10^7 N? You get the correct answer with 3.3*10^7 N.
No im sure its that
this question is straight from a text book.

#### ideasrule

Homework Helper
In that case, the textbook made a mistake.

#### PearlyD

In that case, the textbook made a mistake.
It must have!

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