It is easier to slide a card box when it is empty rather than when it is full with books because of static friction.Friction is the force that resists motion between two surfaces in contact. There are two types of friction: Static friction occurs before a body starts moving. The force squeezing the surface and cardboard is very great when it is full with books. This is why a high force is need to overcome it. Dynamic friction is the resistant to motion of moving body. it is less in value compared to that of static friction.
this a false
the body's situation won't change the forces are equal opposit and on the same body