How does the friction arise between the surfaces of two bodies in relative motion?

A body of mass 2kg is resting on a rough horizontal surface. A force of 20N is now applied to it for 10s, parallel to the surface. If the coefficient of kinetic friction between the surfaces of contact is 0.2. Calculate Work done by the applied force in 10s

Frictional force between solids operates even when they do not move with respect to each other. Do we have viscous force acting between two layers even if there is no relative motion?

A body of mass 2kg is resting on a rough horizontal surface. A force of 20N is now applied to it for 10s, parallel to the surface. If the coefficient of kinetic friction between the surfaces of contact is 0.2. Calculate change in kinetic energy of the object in 10s. (Take g=10ms^(-2) ).

When a person walks on surface the frictional force exerted by the surface on the person is opposite to the direction of motion true or false

A solid sphere of mass 0.50 kg is kept on a horizontal surface. The coefficient of static friction between the surfaces in contact is 2/7. What maximum force can be applied at the highest point in the horizontal direction so that the sphere does not slip on the surface?

The viscous force the relative motion between the adjacent layers of a fluid in motion which one of the following is absolutely fit ?