/sci/ - Science & Math

[Anonymous No.9934906]

>The law of conservation of energy, a fundamental concept of physics, states that the total amount of energy remains constant in an isolated system. It implies that energy can neither be created nor destroyed, but can be change from one form to another.

Let's say I am inside an isolated system, and it's a room isolated from everything else. I walk from one side of the room to the other side and then back to where I stood. I transformed the energy in the chemicals in my cells into heat, some new chemical "waste" compounds and into movement, but in the end, I'm standing on the same place. How come the energy didn't get lost in movement? Where is the energy used for movement now? I'm still standing where I stood.
I'm not trying to disprove the fundamental laws of physics, I just don't understand this shit. Can anyone explain?

[Anonymous No.9934938]

I think you're making the beginners mistake of thinking of energy as some thing or some substance. It's literally a bunch of numbers, or a score keeping table if you like.

[Anonymous No.9934952]

>>9934906
> get lost
The room is now warmer

[Anonymous No.9934969]

>>9934906
Work is a path variable, not a state variable.

Review your high-school textbook you fucking retard.

[Anonymous No.9934970]

>>9934906
Well you’re assuming the enclosed system is small.

Say the enclosed room is a circular hallway with a radius of 100 miles, so a circumference of around 600 Miles. Now say you walked the entirety of the room. You end up at the same place but I’m willing to bet by the time you’re done you’ll be fucking tired and possibly hungry. You’re body used up the chemical energy it had to make kinetic energy which left as heat, entering the room. Your body indeed used energy.

But given the volume of the room it is unlikely that a small amount of heat from your body would warm up the room to a noticeable level.

Same applies in the small room but you can’t notice the energy being lost. If you walk on foot forward and one foot back. You won’t feel tired or even perceive a change in energy, but it’s there. You lost it

Also friction

[Anonymous No.9934972]

>>9934906
>I transformed the energy in the chemicals in my cells into heat, some new chemical "waste" compounds and into movement
>Where is the energy used for movement now?

[Anonymous No.9934980]

>>9934972
To explain a bit more, here, you expended chemical potential energy. Look up how ATP expends energy in the body.

You have to consider all the potential energy you brought into the isolated system

[Anonymous No.9934992]

>>9934970
>>9934972
I assumed that the energy stored in chemical compounds got transformed into
1. heat energy, lost in the room
2. kinetic energy lost in transporting me
I get that the room got warmer, but what happened to the kinetic energy? Did the kinetic energy after I stopped moving myself transform into some other kind of energy?

[Anonymous No.9935005]

>>9934992
>I get that the room got warmer, but what happened to the kinetic energy?

[Anonymous No.9935007]

>>9934992
>Did the kinetic energy after I stopped moving myself transform into some other kind of energy?
Yes

[Anonymous No.9935012]

>>9935005
>>9935007

But how? My body colliding into gas particles while moving? Is this where the kinetic energy got lost?

[Anonymous No.9935013]

>>9934992
Kinetic energy is a Concept for calculating how much energy is needed for movement it doesnt really exist

[Anonymous No.9935016]

>>9934992
You stop moving BECAUSE the kinetic energy gets transformed into waste heat etc.

[Anonymous No.9935026]

>>9935012
Your feet stuck to the floor by friction and your muscles contracted to stabilize you into a standing position. The net energy expenditure went into a bit of heat, but also some kinetic energy and momentum transferred to the room itself, where it's completely unnoticeable since you're a small mass of around 150kg vs a multiple million ton planet.

[Anonymous No.9935030]

>>9935012
Your kinetic energy was dissipated as heat through friction. This friction comes from air resistance, internal friction in your joints/muscles, and friction between you and the ground (main cause).

[Anonymous No.9935049]

>>9935026
>>9935030
Thanks, finally some explanation my brainlet self can understand

[Anonymous No.9935668]

>>9934906
You exhaled a bunch of CO2