Solve the all parts of given problem:
Problem: Blocks with masses of 3.0 kg, 4.0 kg, and 5.0 kg are lined up in a row on a frictionless table. All three are pushed forward by a 19N force applied to the 3.0 kg block.
Part A: How much force does the 4.0 kg block exert on the 5.0 kg block?
Part B: How much force does the 4.0 kg block exert on the 3.0 kg block?
Please provide all work and steps and equations you used for above problem.