A block is pushed 1.5 m along a horizontal tabletop with horizontal force of 2.4 N. If the frictional force between the surface in contact is 0.6 N, what is (i) work done on the block by the frictional force and (ii) the total work done on the block?

Given,

Distance (d) = 1.5 N

Horizontal force ($F_H$) = 2.4 N

Frictional Force ($F_C$) = 0.6 N

(i) Work done by the frictional force ($W_f$) = $F_c * d$ = $-0.6 * 1.5$ = $-0.9 \; Joule$

(ii) Work done by the horizontal force ($W_H$) = $F_H * d$ = $2.4 * 1.5$ = $3.6 \; Joule$

Now, 

Total work done ($W$) = $W_f$ + $W_H$ = $3.6 - 0.9$ = $2.7 \; Joule$