- #1

g.uricchio

- 5

- 0

## Homework Statement

Two forces F

_{1}and F

_{2}are acting on a mass m=6.0 kg. The force F

_{1}= 7.0i + 4.0j + 3.0k, in N. The acceleration of the mass is given by a = 2.0i + 7.0j + 4.0k, in m/s

^{2}. Calculate the magnitude of F

_{2}.

## Homework Equations

F=m*a

## The Attempt at a Solution

F

_{1}+F

_{2}=m*a

F

_{2}=(m*a)-F

_{1}

Magnitude of F

_{1}

^{2}=7

^{2}+4

^{2}+3

^{2}

Magnitude of F

_{1}=8.6 N

Magnitude of a

^{2}=2

^{2}+7

^{2}+4

^{2}

Magnitude of a=8.31 m/s

^{2}

so...

shouldnt F

_{2}=(6.0 kg * 8.31 m/s

^{2}) - 8.6 N ?? (which is 41.24 N)The website where I submit my answer tells me that I am wrong please help me out.

Thankss!

--Graham