Question

Look at the given figure and answer the following questions:

Is it true that there is friction between the box and the floor and also between the boy's feet and the ground?

Answer 1

1. The frictional force is a contact force that acts between two surfaces in contact.
2. On a microscopic level, even a smooth-looking surface has irregularities.
3. When an object is placed over another object these irregularities get interlocked and oppose the motion.
4. Therefore frictional force always acts opposite to the direction of motion or opposite to the direction of applied force.
5. Since the box and boy's feet are moving relative to the floor it means frictional force will act between them.
6. Hence it is true that there is friction between the box and the floor and also between the boy's feet and the ground as shown in the diagram.