Plotting the graph of pendulum period versus length

Click For Summary

Discussion Overview

The discussion revolves around the relationship between the time period of a pendulum and its effective length, specifically focusing on the mathematical reasoning behind squaring the time period when plotting graphs. Participants explore the implications of this transformation in the context of deriving the formula for the pendulum's period.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Conceptual clarification

Main Points Raised

  • One participant questions the necessity of squaring the time period (T) when plotting the graph of the pendulum's period against its length, seeking clarification on its role in the formula T=2∏√(l/g).
  • Another participant suggests that squaring T is for convenience, noting that the graph will still yield a parabola regardless of squaring, as long as T and l are positive.
  • A different viewpoint indicates that plotting T² against l or T against √l can yield a straight-line graph, with the former being easier if a square-root function is unavailable on a calculator.
  • Additionally, one participant elaborates on the general principle that transforming equations to produce linear relationships simplifies the identification of relationships between quantities, asserting that squaring the equation results in a straight line when plotting T² against l, with a specific gradient related to the constants involved.

Areas of Agreement / Disagreement

Participants express differing views on the necessity and implications of squaring the time period, indicating that multiple competing perspectives remain without a consensus on the best approach or reasoning.

Contextual Notes

The discussion does not resolve the underlying assumptions about the relationship between T and l, nor does it clarify the mathematical steps involved in deriving the linear relationship from the original equation.

Revin
Messages
3
Reaction score
0
why do we square the value of T ( time period) while plotting the graph of effect on time period of a pendulum with change in its effective length ?

also while deriving the formula of
T=2∏√(l/g)

why do we take T^2 = 1/g.

Whats the need for squaring the time period ?
 
Physics news on Phys.org
Because for the convenience. even if you don't square Timeperiod nothing will change, you will always get a parabola with T>0 and l>0
 
To get a straight-line graph, you can plot either T2 versus l, or T versus √l. If your calculator doesn't have a square-root key, the first method is easier.
 
More generally if you are trying to identify the relationship between two quantities it is difficult to look at a curve and say it is an arc of a circle, parabola, hyperbola, exponential or whatever. However it is much easier to recognise a straight line. So we transform the equation to produce a linear relationship. In this case squaring the equation gives a straight line by plotting t2 against l.
This gives a straight line whose gradient would be is 4∏2/g.
 

Similar threads

  • · Replies 36 ·
2
Replies
36
Views
4K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
11
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K