kinetic energy

[monty2311]

hi, does anyone know how many joules of kinetic energy the average person uses in a day?

[DJerba]

Kinetic energy is the energy that a body (not as in human body, as in object) possesses because it is moving
it is the energy required to halt that object, or to change it from stationary to moving at a specific speed it is not something that you use, like electricity.

It is = 1/2mv^2 half mass times velocity squared
for non relativistic speeds so, if you're moving fast then it's actually an endless sum of terms kinetic energy squared = 1/(1-(v/c)^2) where c=speed of light in a vaccuum sry, not kinetic energy that value times mc^2 is kinetic energy

Been a while since I've done physics!

[jake-the-peg]

Looking at it like this, a 70 Kg man uses 4-6 Kilojoules a minute sleeping that's say 7,200Kjoules a day.

http://www.healthyeatingclub.com/info/books-ph ds/books/foodfacts/html/maintext/fig12.html

The same man has a reccomended daily intake of about 12,200

http://www.healthyeatingclub.com/info/books-ph ds/books/foodfacts/html/maintext/fig11.html

So very roughly subtracting the one from another gives you 5,000 Kjoules.

There are a load of assumptions in there like not accounting for the heat generated in exercise and the efficiency of turning food into kinetic energy but it should give you an order of magnitude