Here's why:
* Work is defined as the product of the force and the displacement in the direction of the force.
* If the force is perpendicular to the displacement, the work done is zero. This is because the force doesn't contribute to moving the object in that direction.
* If the force is at an angle to the displacement, only the component of the force parallel to the displacement does work.
In summary:
* Work is done when a force causes a displacement in the same direction as the force.
* Force perpendicular to displacement does no work.
* Only the component of force parallel to displacement does work.
Let me know if you'd like to explore specific examples!
