Ram and lqbal has to push two boxes of the same size on the same floor . but ram had to exert more force . What can be the possible reason for this
Answers
Since both the boxes rest on the same floor, the coefficient of static friction is nothing to worry about. What you have to worry about is the normal force because limiting friction is coefficient of static friction times the normal force. Also, the boxes are of the same size implying the volume of both is the same. However, they have not specified anything about density. So, it is logical to assume one of the boxes to have a greater density. Since density is mass over volume, the box with a greater density will have more mass. The gravitational force acting on the heavier box is greater than that acting on the lighter one. Knowing that the box is in vertical equilibrium, it is evident that the normal force is equal to the gravitational force. So, the heavier box will experience greater normal force. This tells us that the heavier box will have a higher value of limiting friction. It is therefore difficult to push the heavier one. You would have to exert a greater force to give rise to an acceleration equal to that of the lighter box. So Ram was pushing the denser box or in this context, the heavier box