Three masses from left to right 0.30kg, 0.40kg, and 0.20kg are connected by a light cords to make a "train" sliding on a frictionless surface. They are accelerated by a constant horizontal force of 1.5N that pulls at the rightmost mass to the right.
A) what is the tension in the cord between 0.30 and 0.40 masses
B) what is the tension between 0.40 and 0.20 masses