Calculating Acceleration and Tension in a Two-Block System with Friction

[wolves5]

A block of mass m1 = 2 kg and a block of mass m2 = 3 kg are tied together and are pulled from rest across the floor by a force of Fp = 30 N. The coefficient of friction of the blocks with the floor is µ = 0.23.

a) What is the acceleration of the two blocks?

For this question, I used Newton's Second Law. I used F=ma. I did 30=(5 kg)(a). I got 6 m/s2 for the acceleration, but that's not right. How do I do the acceleration then?

b) What is the tension in the string between the blocks?
I think I can do b if I get the accelration from part a. I think the equation is T=ma.

 

[Yuqing]

For a, you're forgetting friction in the net force sum. Try b after you get a.

 

[wolves5]

Is that Fk=(mew)(mass)(acceleration)? But then what's Fk?

 

[Yuqing]

I think you're misunderstanding what exactly the coefficient of kinetic friction is. It is the ratio of the frictional force to the normal force of the object.