Which statement best explains why running on a track with constant speed at 3 m/s is not considered work, but climbing a mountain at 1 m/s is considered work?
1) Work is only done when there is a displacement in the direction of the force applied.
2) Work is only done when the speed is constant.
3) Work is only done when the force applied is greater than the weight of the object.
4) Work is only done when the distance covered is greater than 1 meter.