Question

Is work done if you carry a book across the room at a constant velocity?

Answer 1

Answer:

NO

Explanation:

As we know by work energy theorem that work done by all forces is given by change in kinetic energy of the system

it is given as

$W_{net} = KE_f - KE_i$

so here since the kinetic energy is constant for the system

so here change in kinetic energy is zero

hence the net work done must be zero

Here we know that

$v_i = v_f$

so here we can say that

$\Delta KE = 0$

so no work is required to move the books at constant speed from one position to other position

Answer 2

Yes because it has been moved from its original point. if had stayed inone spot or had been dropped no work would have been done.