Question

What is the Internal energy of a falling ball??

Answer 1

@experimentX , @Siddharth18 , Is Internal energy = Potential energy??

Answer 2

@ketz is the question in context of mechanics or thermodynamics?

Answer 3

Thermodynamics question!

Answer 4

if that's the case then i guess @shivam_bhalla has got it right

Answer 5

I would say , do you want to consider friction and other viscous force in air? If yes, then falling ball internal energy increases

Answer 6

I think it has zero internal energy since there is no change in the kinetic and potential energies of the molecules found inside the ball!!!

Answer 7

ΔU=0 I think!

Answer 8

but one thing confuses me we have considered only the gravitational potential energy but what about the bond energy and static electric energy which constitute the total potential energy of the system

Answer 9

@ketz if u luk from an inertial frame ,the molecules will be having KE

Answer 10

@Siddharth18 is absolutely right :)

Answer 11

Looks like you are still not convinved @ketz . Imagine you are sitting in a train and you are seeing a passenger sit next to you . For you he appears stationary. Why?? because you are viewing from non-inertial reference. If you are looking from ground, you will see the passenger moving(i.e having Kinetic energy). Hopefully this brings clarity to you

Answer 12

Hi! Better go back to definitions! Have a look at the words at the end of the second sentence.
This is why internal energy is called 'internal'!
http://en.wikipedia.org/wiki/Internal_energy

Answer 13

@Vincent-Lyon.Fr , looks like you are right and I am wrong . :D . and the answer to the question is zero @ketz

Answer 14

@shivam_bhalla: You gave the answer to the question: "What is the CHANGE in internal energy for a falling ball"

The question was : "What is the Internal energy of a falling ball?"
So the answer must be: "The same as when it is at rest".