Question

A horizontal force 'f' equals 6 mg is applied on block A as shown. Normal reaction between block A and B will be​

Answer 1

Answer:

2mg

Explanation:

since friction is 0, acceleration of combined mass is

force/total mass = 6mg/3m = 2g

now both A and B has an acceleration of 2g in common

consider free body diagram of A

force F and normal force due to B will be in opposite direction. ( let normal force between A and B be N )

so the net force on A is (6mg - N ) and its acceleration is 2g

now according to f = ma , ( 6mg - N )/ ( 2m ) = 2g

simplifying this, you get N = 2 mg

same goes with B.

Hope this helps you....