Proof that gravity equals 9.8 metres per second?

  • Thread starter Thread starter EasyTheySaid
  • Start date Start date
  • Tags Tags
    Gravity Per Proof
Click For Summary

Homework Help Overview

The discussion revolves around confirming the acceleration due to gravity, commonly approximated as 9.8 meters per second squared. Participants explore methods for measuring this value through experiments involving dropping objects and considering factors such as air resistance and variations in gravitational acceleration based on location.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the feasibility of measuring gravity by dropping objects from different heights and calculating acceleration based on time and displacement. There is a focus on the need to eliminate air resistance for accurate measurements, and some question the validity of the proposed methods.

Discussion Status

Several participants have offered insights into the challenges of measuring gravity accurately, including the impact of air resistance and the necessity of specific conditions for precise results. There is acknowledgment of the limitations of common methods and a recognition of different experimental approaches being considered.

Contextual Notes

Participants note that the measurement of gravity can be affected by environmental factors such as air friction and geographical variations, which are under discussion but not resolved.

EasyTheySaid
Messages
5
Reaction score
0
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
 
Last edited:
Physics news on Phys.org
the experiment won't 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 .
 
kushan said:
the experiment won't 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
 
kushan said:
, you need to eliminate air resistance

Thank you
 
You're method is good enough for a first order approximation.
 
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.
 
Integral said:
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 .
 
  • #10
Galileo used the inclined plane.
 

Similar threads

Replies
3
Views
1K
Replies
18
Views
2K
  • · Replies 38 ·
2
Replies
38
Views
4K
Replies
7
Views
2K
  • · Replies 47 ·
2
Replies
47
Views
3K
Replies
8
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 22 ·
Replies
22
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K