No Stupid Questions

4,467 readers

632 active

68 users here now

There is no such thing as a Stupid Question!

Don't be embarrassed of your curiosity; everyone has questions that they may feel uncomfortable asking certain people, so this place gives you a nice area not to be judged about asking it. Everyone here is willing to help.

ex. How do I change oil
ex. How to tie shoes
ex. Can you cry underwater?

Reminder that the rules for lemmy.ca still apply!

Thanks for reading all of this, even if you didn't read all of this, and your eye started somewhere else, have a watermelon slice 🍉.

founded 4 years ago

moderation log

moderators

admin@lemmy.ca

If energy is movement, how come I get tired just from holding a heavy object? (multiverse.soulism.net)

submitted 1 month ago by Grail@multiverse.soulism.net to c/nostupidquestions@lemmy.ca

14 comments fedilink hide all child comments

In high school physics, I learned that the equation for energy from moving something is a factor of force and displacement. So if an object remains stationary, then no matter how much force is put into it, no energy is expended.

So how come if I hold a heavy box filled with dumbbells, I get tired? I'm obviously putting a lot of newtons into it to keep it from falling, but it's not moving. So how is the weight of the object causing Me to expend energy?

you are viewing a single comment's thread
view the rest of the comments

[–] scallisto@retrofed.com 2 points 1 month ago

Energy is not movement. Kinetic energy comes from movement (half mv squared!)

You need to account for thermal, chemical, potential, elastic potential, electric, etc. energies

Energy is being expended as your muscles are working against the force of gravity to hold the object up!

permalink

fedilink

source