Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: RJFarmer on 28/10/2006 12:53:01
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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.
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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'.
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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.
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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.
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I thought you were going to do something more subtle than weigh a 1 Kg mass on a spring balance calibrated in Newtons!
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I know. Sometimes it's difficult to think about the simpler thing. Even this is something I didn't learn at once!