Physics
posted by Help Please on .
You are pulling your little sister on her sled across an icy (frictionless) surface. When you exert a constant horizontal force of 114 N, the sled has an acceleration of 2.3 m/s2 If the sled has a mass of 7.6 kg, what is the mass of your little sister?
I don't need the answer, just help on how to solve it. Thanks

(m1+m2)a=F
m1+m2 =F/a
m2=F/a – m1 
Thank you very much Elena for that and also for promptly answering my question on a timely manner!!!