Three blocks A, B and C of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless surface. If a force of 7 N is applied on the 4 kg block, then the contact force between A and B is :
1
3 N
2
4 N
3
9 N
4
1 N
Three blocks A, B and C of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless surface. If a force of 7 N is applied on the 4 kg block, then the contact force between A and B is :