Posted by Kayleigh on .
Two blocks are in contact on a frictionless table. A horizontal force F is applied to M2, as shown. If M1 = 1.06 kg, M2 = 3.80 kg, and F = 4.85 N, find the size of the contact force between the two blocks.
If instead an equal but oppositely directed force is applied to M1 rather than M2, find the size of the contact force between the two blocks.

Physics 
MathMate,
F=>M2=>F1=>M1
On the frictionless table, both will have an acceleration a.
Draw the freebodydiagrams (FBD) and conclude that
M2.a = (FF1)
M1.a = F1
using Newton's second law.
Solve for F1 and a.
Part (b) can be found in a similar way.