In a moving block, a variable force pushes it. Friction is acting against the movement.
Below equation specify the amount of energy could be used to give motion: $$ E_1 = \int F_T(t) .v(t) .dt $$
However, because of friction,energy used to give motion gets smaller:
$$ E_2= \int [F_T(t)-F_R].v(t).dt $$
Can I assume E2 as energy used to give motion and E3 as dissipated energy due to the friction? $$ E_3=\int F_R(t).v(t).dt $$