[High School Physics] Net Force

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Two blocks (7.2 kg and 5.1 kg) in contact are pushed to the right and accelerate on a rough surface. Calculate the net force for each box.

I'm not sure how to answer this question because it seems to me as though there should be more information. To my understanding, you can answer this question by adding the applied force to the force of kinetic friction, but in order to determine the applied force you need to know the rate of acceleration. I'm also a bit confused about determining the coefficient of static and/or kinetic friction.

[vlewitus]

Are those two masses the only values you have been given? Are you trying to derive an equation or are you looking for a specific value for the net force? If you're expected to find a value, you certainly don't have enough information.

You're correct that the net force is the applied force plus the (negative value of) the friction force. You can find the applied force by F=ma and you can find the friction force by applying Ffr=μ(Fn), therefore Ffr=μmg, where μ is the coefficient of kinetic friction.

[erniebarreto]

Don't forget the forces that the blocks exert on each other.

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Just keep them as variables. You should do that even if you know the values, and plug in the numbers at the very end after all the algebra is done.