# Does the mass of a spring decreases if we compress it because we have stored energy?

1. Aug 25, 2009

### I_am_learning

I mean to ask is every Energy storage or production associated with mass change?

2. Aug 25, 2009

### jacksnap

Re: Does the mass of a spring decreases if we compress it because we have stored ener

The mass of the spring will increase when compressed as the system contains MORE energy.

And yes every energy storage/change will have an associated effect on mass.

3. Aug 26, 2009

### bm0p700f

Re: Does the mass of a spring decreases if we compress it because we have stored ener

Edit My post has confused me now. Can someone please confirm is jacksnap is right. It would mean my original thinking is good and my later later confused thinking is wrong.

Last edited: Aug 27, 2009
4. Aug 26, 2009

### I_am_learning

Re: Does the mass of a spring decreases if we compress it because we have stored ener

bm0p700f has confused me. I need clarification please!!!

5. Aug 27, 2009

### Bob S

Re: Does the mass of a spring decreases if we compress it because we have stored ener

I think jacksnap is correct. I have seen the following experiment. Get two identical springs. Compress one and tie it up with string, and attach one end of a copper wire to each spring. Put both in a mild sulfuric acid solution (maybe 1N). Is the action of the acid on the two springs different (bubbles, etc.). Why?

6. Aug 27, 2009

### jacksnap

Re: Does the mass of a spring decreases if we compress it because we have stored ener

LOL, now I need clarification,

I was always under the impression that the more energy a system has, the more mass it has. (although only very very slightly)

ie, a charged battery has more mass then one with no charge, so i assumed it was the same for a compressed spring.

7. Aug 27, 2009

### Bob S

Re: Does the mass of a spring decreases if we compress it because we have stored ener

Yes, the compressed spring has more energy. But it is unlike a battery, because no charge transfer is required. The extra energy is in the displacement of individual atoms from their minimum energy state (mechanical stress). In terms of mass of the spring; the extra stored energy has to increase the mass of the spring by a minscule amount.

8. Aug 30, 2009

### I_am_learning

Re: Does the mass of a spring decreases if we compress it because we have stored ener

Understood this. Thanks everybody. Don't like to loose mass my spending more energy by typing, so bye!!!