What are the conditions for different types of damping in oscillations?

Click For Summary
SUMMARY

The discussion focuses on the conditions for underdamped, overdamped, and critically damped oscillations in a mass-spring-damper system. The mass m is 0.80 kg, and the damping coefficient γ is 1.18 kg/s, leading to a calculated spring constant k of 0.435 N/m for critical damping. The solution for the displacement x(t) under critical damping is given by x(t) = (A + Bt)e^(-βt), where β = γ/(2m). The user seeks clarification on solving for time t when the displacement is a/2, having initially calculated t as 2.28 seconds.

PREREQUISITES
  • Understanding of Newton's second law and basic mechanics
  • Familiarity with differential equations and their solutions
  • Knowledge of damping types: underdamped, overdamped, and critically damped
  • Ability to manipulate and solve equations involving exponential functions
NEXT STEPS
  • Study the derivation of the critical damping condition in oscillatory systems
  • Learn how to apply the Laplace transform to solve differential equations in physics
  • Explore the effects of varying the damping coefficient γ on oscillation behavior
  • Investigate the relationship between mass, spring constant, and damping in mechanical systems
USEFUL FOR

Students in physics or engineering, particularly those studying dynamics and oscillatory motion, as well as educators looking for examples of critically damped systems.

kraigandrews
Messages
105
Reaction score
0

Homework Statement



A mass m moves in one dimension x subject to a restoring force −kx and a damping force −γ[(x)\dot]. What are the conditions for underdamped oscillations, overdamped oscillations, and critical damping?
Now, suppose m is 0.80 kg, γ is 1.18 kg/s, and the oscillations are critically damped. What is k?

The object starts at rest, displaced by some amount a. At what time is the displacement a/2?

Homework Equations



\beta=\gamma/(2m)

The Attempt at a Solution



Ok so I know k=0.435 N/m

and I know the solution for the diff eq for critical damping is:

x(t)=(A+Bt)e^(-\betat)

my problem then becomes solving for A and B.
from the given info I would think x(0)=a and x'(t)=0
giving me A=a and B=\betaa.

I am not sure if this because when I solve for t at x(a/2) I do not get the right answer
 
Physics news on Phys.org
How did you solve for t? I found t=2.28 s.
 

Similar threads

Replies
5
Views
1K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
9
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 11 ·
Replies
11
Views
2K
Replies
3
Views
958
Replies
2
Views
2K
Replies
7
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
17
Views
3K