Question

Three blocks a, b and c, of masses 4kg,2kg and 1kg respectively, are in contact on a frictionless surface, as shown. If a force of 14n is applied on the 4kg block, then the contact force between a and b is:

Answer 1

Hey
here it is

Given, mA = 4 kg
mB = 2 kg 
=> mC =1 kg

So total mass (M)  = 4+2+1 = 7 kg
Now, F = Ma 
14 = 7a
a=2 m/s2


F-F' = 4a
F' = 14-4x2
F' = 6N

Answer 2

Answer:

,this is the best i can do....