Question

Two cardboard boxes full of books are in contact with each other on a frictionless table.box H has twice the mass of boxG .if you push on box G with a horizontal Force F,then box H will experience a net force of

Answer 1

The force exerted by box G on H  = F 
Weight acting acting of H  = mg downwards
The force exerted by box of table  = mg downwards
The reaction force by the table = mg upwards
These forces cancel

The remaining force acting is F. 
Net force  = F. There is no friction