Question

The horse lifted a large force (50 N up) and traveled 5 m to the left. Why didn't the horse do a lot of work? Explain.

Answer 1

\[F=work \times displacement\]
but the displacement of force wid resp. to horce is zero so no work done

Answer 2

That equation isn't right.

Work = (Force) x (distance/displacement in the direction of the force)

For example, if I pick up a book from the floor, I have to do work because I am moving the book in the opposite direction of the gravitational force.

But if I carry a book across the room from one table 1 m high to another table 1 m high, then the displacement of the book in the direction of the force is zero.

The force due to gravity is in the negative vertical direction; i.e., it is in the downward direction. Moving a book horizontally means the displacement in the direction of the force is zero.

Hence in the book example, the work done is zero.

Your horse question is pretty much identical.