A heavy piano is pushed up an inclined plane into a moving van. Which of the following choices best explains how the inclined plane made the task easier?
1. The force needed to move the piano up the plane was less than the force needed to lift it straight up into the van, but the distance over which the piano moved was greater.
2.The force exerted on the piano was the same as if it had been lifted, but the distance it needed to be move decreased, so the total work decreased.
3.The distance that the piano was moved was less that the distance it would have had to be lifted, so the total work decreased.
4. The amount of force need to push the piano up the ramp is the same as the force needed to lift it, so the amount of work remained the same.​