Understanding Work in Physics

Carrying your groceries across the parking lot does absolutely zero work on them. I know,

it feels like a workout, but hear me out. In physics, work is about transferring

energy. You apply force upwards to hold the bag, but you move forwards.

That's a 90-degree angle between your force and the motion. Because of that angle,

no energy is transferred to the groceries, so no work is done on them. Same if you push

a wall. You're using force, but if it doesn't move, the distance is

zero, so the work is zero. For work to happen, your force must actually cause movement

in its direction.