How much work is done when a book weighing 2.0 newtons is carried at constant velocity from one classroom to another classroom 26 meters away?

Answer 1

If the box ended up at the same height above the floor as it started, then

no gravitational potential energy was added to the box in the form of work.

It doesn't even matter if the box moved up or down on the way.

Of course, work is done, and calories are expended. That's only because

your body is not 100% efficient, and it takes work to move arm and leg

muscles, walk, breathe, etc. But no work is done on the box as it moves

horizontally.

Answer 2

First of all, constant velocity is very unlikely. In order to move the book from

one classroom to another at constant velocity, you'd have to be able to stand

in the first classroom, and look straight out of one and into the other, so that

the book's trip can be accomplished at a constant speed and in a straight line.

If any turns are required on the way, then constant velocity isn't possible.

But it certainly does make the question easier to answer. If the book doesn't

speed up or slow down on the way, doesn't curve or turn a corner, and ends up

at the same height above the floor as it started, then no gravitational potential

energy is added to it in the form of work. It doesn't even matter if it moved up

and down on the way ... if it ends up at the same elevation, then work is zero.

Of course, work is done, and calories are expended. That's only because your

body is not 100% efficient, and it takes work to move arm and leg muscles, walk,

breathe, etc. But no work is done on the book as it moves horizontally.

Answer 3

idk