Answer:
(1) 2.4 n
Step-by-step explanation:
The force of kinetic friction between the block and the floor is given by:

where
is the coefficient of kinetic friction
N is the normal reaction of the floor against the block
For a horizontal surface (as in this case), the normal reaction is equal to the weight of the block, so
. For wood-wood contact, the coefficient of kinetic friction is approximately
. Therefore, the force of kinetic friction between the block and the floor is:
