# Conservation of energy

Joined Dec 29, 2004
83
Hi can someone help me with this problem:

If a .75 kg block is rested on the top of a vertical string of force constant 45N/m, how much potential energy is stored in the spring relative to its equqilibrium configuration?

I tried to use the conservation of energy , but it did not let me to a good conclusion.

Thank you

B

#### n9352527

Joined Oct 14, 2005
1,198
Originally posted by braddy@Oct 26 2005, 10:08 PM
Hi can someone help me with this problem:

If a .75 kg block is rested on the top of a vertical string of force constant 45N/m, how much potential energy is stored in the spring relative to its equqilibrium configuration?

I tried to use the conservation of energy , but it did not let me to a good conclusion.

Thank you

B
[post=11263]Quoted post[/post]​
The force exerted down by the block on the spring is

F = mg

The spring is compressed for a length of h due to this force

h = F / force constant

Energy stored is either the potential energy of the block

E = mgh

or the potential energy stored in the string

E = Fh

They are both equal.

Joined Dec 29, 2004
83
Originally posted by n9352527@Oct 27 2005, 03:18 AM
The force exerted down by the block on the spring is

F = mg

The spring is compressed for a length of h due to this force

h = F / force constant

Energy stored is either the potential energy of the block

E = mgh

or the potential energy stored in the string

E = Fh

They are both equal.
[post=11284]Quoted post[/post]​
thank you very much