Physics
Mechanical Work
Quick fact
In physics, if you hold a 50 kg weight above your head without moving it, you do zero mechanical work – even though you feel like you're working hard. Work only happens when something moves.
Why this is interesting
You push a heavy shopping cart across the parking lot, and you feel tired – you've done work. But what if you push against a wall that doesn't move? According to physics, you might are exhausted but have done no work at all. What's the real definition?