Change in amplitude of pendulum

Click For Summary
SUMMARY

The discussion centers on the decrease in amplitude of a pendulum's oscillation over time, primarily due to energy losses from air friction and pivot friction. It emphasizes that an ideal pendulum does not experience amplitude loss, but real-world factors such as air drag, which varies with Reynolds numbers, significantly impact performance. The conversation suggests using a high-density bob, such as lead, and a longer string to minimize these losses.

PREREQUISITES
  • Understanding of pendulum mechanics
  • Familiarity with energy loss concepts in oscillatory systems
  • Knowledge of Reynolds numbers and fluid dynamics
  • Basic principles of drag forces in physics
NEXT STEPS
  • Research the equations governing pendulum motion and energy loss
  • Explore the effects of air drag on oscillating bodies
  • Learn about the properties of materials affecting pendulum performance, such as density and shape
  • Investigate differential equations related to damped harmonic motion
USEFUL FOR

Physics students, mechanical engineers, and hobbyists interested in pendulum dynamics and energy loss in oscillatory systems.

Pathan
Messages
1
Reaction score
0
When we drag the bob at certen heightand relese it. It start's oscelation. and the the apmlitude of the vibration decreases with time.
can anybody help me by giving the equation which tell the decrease in amplitude.
 
Physics news on Phys.org
No, because in general it won't because we assume an ideal pendulum.
If the amplitude decreases there are energy losses which may be due to a variety of factors, most importantly (but not limited to) air friction and possibly friction at the pivot. Unless you make some more assumptions you cannot just write down "the" equation (and even under some set of assumptions, "the" equation will usually be a differential equation which is hard to solve).
 
The amplitude loss is probably due to air drag. There are two types, corresponding to low and high Reynold's numbers. Read http://en.wikipedia.org/wiki/Drag_(physics )
Your pendulum should have a high density bob (lead is better than brass), and as long a string as possible. Note that for a given density bob, the mass is proportional to the cube of linear dimensions, and the frontal area (proportional to drag) scales as the square.
 
Last edited by a moderator:

Similar threads

High School Harmonic oscillator and simple pendulum time period
  • · Replies 36 ·
2
Replies
36
Views
4K
Undergrad How Does Changing Mass and Spring Force Affect Watch Oscillators?
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad On whether the motion of a Foucault pendulum bob is comparable to ballistics
  • · Replies 10 ·
Replies
10
Views
3K
Graduate Pendulum Damping force effect on amplitude over time
  • · Replies 1 ·
Replies
1
Views
3K
Graduate Pendulum is vibrating freely in unforced oscillation
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Modeling the damping of a physical rigid pendulum
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Are the Reasons for Pendulum's Mass and Amplitude Independence Contradictory?
  • · Replies 14 ·
Replies
14
Views
4K
Seeking advice on "simple" pendulum problem
  • · Replies 27 ·
Replies
27
Views
2K
High School Calculating g with a Conical Pendulum
  • · Replies 3 ·
Replies
3
Views
4K
Graduate Rolling Pendulum: Solving the Dynamics Equations
  • · Replies 2 ·
Replies
2
Views
3K