Tug-of-War Forces: Solving the Rope Problem

[whoopie88]

Homework Statement

Suppose a 69-kg boy and a 48-kg girl use a massless rope in a tug-of-war on an icy, resistance-free surface. If the acceleration of the girl toward the boy is 3.0 m/s2, find the magnitude of the acceleration of the boy toward the girl.

Homework Equations

f=ma
fg=mg
fnet=mAnet
Ff=μῦF

The Attempt at a Solution

I don't understand how to solve it. Or draw a free-body diagram...and go from there.

 

[rl.bhat]

Apply Newton's third law.

 

[whoopie88]

I don't understand how that would help me to solve the problem. Can you help me get started please?

 

[whoopie88]

Nevermind, I was asking too much for a simple problem. I understand it now and I solved it. Thank you for your help!