Homework Help: Natural frequency calculated theorectically and experimentally

1. Sep 3, 2007

balogun

1. The problem statement, all variables and given/known data

I was given a spring mass system and asked to calculate the natural frequency by theorectical analysis and by using experimental data.

There was a difference between the natural frequency calculated theorectically and experimentally.

I was asked to discuss the difference in results and I wanted to know if damping is the cause for the difference in results .
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Sep 3, 2007

Astronuc

Staff Emeritus
What was the difference between theoretical and experimental results for natural frequency. Certainly damping would have an effect.

Are the spring constant and mass accurately measured?

3. Sep 3, 2007

balogun

for the theorectical analysis I was given the length of spring, the mass attached and the length of stretched spring.I used that to calculate spring constant and then calculate frequency.

for the experimental I was given the time for 20 oscllations for five different readings.

Found average time ,diivided by 20 to find period and found inverse of period to find frequency.

I think damping has an effecy but I have read online that damping only affects amplitude of oscillation not the period.

4. Sep 3, 2007

Astronuc

Staff Emeritus
The natural frequency is not affected by damping, but the damped frequency can be different. However, the different may not be too different.

http://hypertextbook.com/chaos/41.shtml [Broken]
http://en.wikipedia.org/wiki/Damping
http://hyperphysics.phy-astr.gsu.edu/hbase/oscda2.html#c2

Is the spring constant actually constant over the range of deflection?

Did one measure the relaxed length (unloaded) of the spring before and after the experiment?

Did one use the spring constant determined from the experiment in the theoretical calculations?

Last edited by a moderator: May 3, 2017