A 4.770 kg block of wood rests on a steel desk. The coefficient of static friction…

A 4.770 kg block of wood rests on a steel desk. The coefficient of
static friction between the block and the desk is ?s = 0.655 and
the coefficient of kinetic friction is ?k = 0.155. At time t = 0, a
force F = 18.8 N is applied horizontally to the block. State the
force of friction applied to the block by the table at the
following times: t=o and t>0

Consider the same situation, but this time the external force F is
38.0 N. Again state the force of friction acting on the block at
the following times: t=0 and t>0