# Proof that gravity equals 9.8 metres per second?

If you had to confirm that gravity equals approximately 9.8 metres per second would you take an object and drop it from different heights. Would you then take the time and displacement and work out velocity and then use that to work out acceleration??

EDIT: In this example there is no air resistance

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the experiment wont give exactly 9.8 , since air friction is also there .
You need vacuum or vacuum like condition for 9.8 .
And g also varies with latitudes .

the experiment wont give exactly 9.8 , since air friction is also there .
You need vacuum or vacuum like condition for 9.8 .
And g also varies with latitudes .

That's why I said approximately 9.8.
Is my method correct?

, you need to eliminate air resistance

, you need to eliminate air resistance

Thank you

You're method is good enough for a first order approximation.

Integral
Staff Emeritus
Gold Member
Your measurement errors will be greater then the effects of air resistance unless you have some pretty exotic equipment.

The traditional method for doing this was to fasten a strip of waxed paper tape to your weight and feed it through a sparker with a know rate. The distance between the dots give you the displacement in fixed time intervals.

Your measurement errors will be greater then the effects of air resistance unless you have some pretty exotic equipment.

The traditional method for doing this was to fasten a strip of waxed paper tape to your weight and feed it through a sparker with a know rate. The distance between the dots give you the displacement in fixed time intervals.

I understand. Like the "ticker tape"?

And you can also make a pendulum of a heavy mass , light spring .
Calculate its time period ( keep the amplitude small ) , and plug it in the equation of of time period , you can find g , pretty close enough .

Galileo used the inclined plane.