# The Naked Scientists Forum

### Author Topic: acceleration of gravity in a spring?  (Read 8157 times)

#### RJFarmer

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##### acceleration of gravity in a spring?
« on: 28/10/2006 12:53:01 »
Hi, in one of my recent physics classes the teacher mentioned that you could find the acceleration due to gravity by using a spring and the spring constant.
I've looked on the internet and I can't really find out how it is done, can anyone here help me out? or point me in the right direction?

Many thanks.
« Last Edit: 28/10/2006 13:38:47 by RJFarmer »

#### syhprum

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##### Re: acceleration of gravity in a spring?
« Reply #1 on: 28/10/2006 13:28:37 »
The Gravitational constant is a very small quantity beyond the resources of any school physics lab to measure.
The only thing I think your teacher may have in mind is to take an estimate of the mass of the Earth based on its volume and its assumed specific gravity (about 5.0) and then measure the acceleration due to this mass (about 9.81 m/s/s ) and work back from there.
more details are available from 'Gravitational constant' in 'Wikipedia'.

#### RJFarmer

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##### Re: acceleration of gravity in a spring?
« Reply #2 on: 28/10/2006 13:38:30 »
well I'm pretty sure that he said that we could be able to do it in class.
and maybe I should edit my original post, its supposed to be the acceleration due to gravity not of gravity. I dont know if that makes a difference.

#### lightarrow

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##### Re: acceleration of gravity in a spring?
« Reply #3 on: 28/10/2006 19:35:17 »
A body's weight is P = m•g
weight is equilibrated from the spring: m•g = k•Δx
where k is the spring's elastic constant and Δx its extension
so g = k•Δx/m.
low level physics.

#### syhprum

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##### Re: acceleration of gravity in a spring?
« Reply #4 on: 28/10/2006 20:22:53 »
I thought you were going to do something more subtle than weigh a 1 Kg mass on a spring balance calibrated in Newtons!

#### lightarrow

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##### Re: acceleration of gravity in a spring?
« Reply #5 on: 29/10/2006 10:03:40 »
I know. Sometimes it's difficult to think about the simpler thing. Even this is something I didn't learn at once!

#### The Naked Scientists Forum

##### Re: acceleration of gravity in a spring?
« Reply #5 on: 29/10/2006 10:03:40 »