Damped Simple Harmonic oscillator

In summary, the damped simple harmonic oscillator with a mass of 260 g, spring constant of 95 N/m, and damping coefficient of 75 g/s has an amplitude ratio of Adamped / Ainitial at the end of 20 cycles. To calculate this ratio, first use the equation for frequency to determine the time taken for 20 cycles. Then, use the expression for amplitude to calculate the amplitude after that time. Finally, take the ratio of the two amplitudes to get the desired result. Additional help and resources can be found at www.geocities.com/physics_all.
  • #1
GingerBread27
108
0
a damped simple harmonic oscillator has mass m = 260 g, k = 95 N/m, and b = 75 g/s. Assume all other components have negligible mass. What is the ratio of the amplitude of the damped oscillations to the initial amplitude at the end of 20 cycles (Adamped / Ainitial)?

having trouble getting started, any help?

I know the equations, just not how to use them :frown:
 
Physics news on Phys.org
  • #2
Calculate the time taken for 20 cycles from the equation for frequency that you have. (Reciprocal of frequency is the time taken for one oscillation.)

Then, calculate the amplitude after that time from the expression for amplitude.
Now just take the ratio.


Spacetime
www.geocities.com/physics_all
 
  • #3


No problem, let's break it down step by step. First, we need to understand what a damped simple harmonic oscillator is. It is a system where a mass is attached to a spring and is subject to a damping force, which is a force that opposes the motion of the mass. This results in the amplitude of the oscillations decreasing over time.

Now, to solve for the ratio of the amplitude of the damped oscillations to the initial amplitude at the end of 20 cycles, we can use the equation:

Adamped / Ainitial = e^(-bt/2m)

In this equation, e is the base of the natural logarithm, b is the damping coefficient, t is the time, and m is the mass.

We are given the values for m, k, and b, so we just need to plug them into the equation. Since we are looking at the end of 20 cycles, we can assume that t = 20T, where T is the period of the oscillations.

To find the period, we can use the equation T = 2π√(m/k). Plugging in the values, we get T = 0.12 s.

Now, we can plug in all the values into the original equation:

Adamped / Ainitial = e^(-bt/2m)

= e^(-0.075*20*0.12/2*0.26)

= 0.491

Therefore, the ratio of the amplitude of the damped oscillations to the initial amplitude at the end of 20 cycles is approximately 0.491. This means that the amplitude of the oscillations will decrease by about half after 20 cycles.

I hope this helps you understand how to approach and solve problems involving damped simple harmonic oscillators. Remember to always start by understanding the concept and then plugging in the given values into the appropriate equations. Good luck!
 

FAQ: Damped Simple Harmonic oscillator

What is a damped simple harmonic oscillator?

A damped simple harmonic oscillator is a system where a mass is attached to a spring and experiences a restoring force that is proportional to its displacement from equilibrium. However, in this system, there is also a damping force that acts against the motion, causing the amplitude of the oscillations to decrease over time.

What is the equation of motion for a damped simple harmonic oscillator?

The equation of motion for a damped simple harmonic oscillator is m¨ + b·x´ + k·x = 0, where m is the mass, b is the damping coefficient, k is the spring constant, and x is the displacement from equilibrium.

How does the damping coefficient affect the motion of a damped simple harmonic oscillator?

The damping coefficient, b, determines the strength of the damping force. A higher damping coefficient means that the damping force is stronger and will cause the amplitude of the oscillations to decrease faster, resulting in a quicker decay of the motion.

What is the difference between an underdamped, critically damped, and overdamped oscillator?

An underdamped oscillator experiences a damping force that is less than the critical value, resulting in oscillations that gradually decrease in amplitude. A critically damped oscillator experiences a damping force equal to the critical value, resulting in the quickest decay of the motion. An overdamped oscillator experiences a damping force that is greater than the critical value, resulting in a motion that returns to equilibrium without any oscillations.

What are some real-world examples of damped simple harmonic oscillators?

Some examples of damped simple harmonic oscillators include car suspensions, pendulums in air, and the movement of a door when it is opened and then allowed to close on its own. In these systems, the presence of air resistance or friction causes the oscillations to gradually decrease in amplitude over time.

Back
Top