The mass of the block as given in the question is 2kg.
The coefficient of static friction is 0.4.
Force applied on the block is Fnet = 2.8N
The force of friction between the block and the floor =?
Limitng friction =μN = 0.4 × 2 × 10 = 8N
As applied force is less than limiting friction
so Force of friction on block=Applied external force=7N