Problem 4-35.

(a)

(b)

(c)

(d)

(e)

(f)

Yes, the answers make sense intuitively. The acceleration is given by the external force F divided by the total mass of all three blocks. Since F is only applied to m₁, the contact force between m2 and m3 is simply the force needed to accelerate m₃. Similarly, the contact force between m₁ and m₂ is the force needed to accelerate m₂ + m₃.