Did I Make a Mistake in My Spring Constant Calculation?

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Homework Help Overview

The discussion revolves around calculating the spring constant and the theoretical period of oscillation for a spring system. The original poster presents measurements and calculations, expressing confusion over discrepancies between theoretical and experimental results.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants explore the relationship between the spring constant and the period of oscillation, questioning the units used in calculations. There is a focus on the mass variable and its correct unit representation.

Discussion Status

Some participants have offered insights into unit conversions and the importance of maintaining consistent units throughout calculations. There is ongoing exploration of the implications of using incorrect units, particularly regarding the mass and spring constant.

Contextual Notes

Participants are discussing potential errors in unit conversions and the definitions of variables involved in the calculations. The original poster seeks clarification on the proper units for mass and force in the context of their calculations.

squashen
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The goal is to measure the spring constant of a spring and then calculate a theoretical period of the oscillation and compare the results to a real life measurement.

Extension of spring A:
Neutral: 52 cm
1 N: 41 cm
2 N: 30 cm
F = kx
k = 9.1 N/m

10 oscilliations = 9.26 seconds

Calculating the theoretical period for 2 Newton:
t=2pi*sqrt(m/k)
t=2pi*sqrt(2/9.1)=2.9 which is completely wrong compared to the real life result.
If i set k to 91 instead of 9.1 the resulting period is 0.93, much closer to reality.

Have I botched up the units along the way or what have I done wrong?

I'd be very greatful for help.
 
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squashen said:
The goal is to measure the spring constant of a spring and then calculate a theoretical period of the oscillation and compare the results to a real life measurement.

Extension of spring A:
Neutral: 52 cm
1 N: 41 cm
2 N: 30 cm
F = kx
k = 9.1 N/m

10 oscilliations = 9.26 seconds

Calculating the theoretical period for 2 Newton:
t=2pi*sqrt(m/k)
t=2pi*sqrt(2/9.1)=2.9 which is completely wrong compared to the real life result.
If i set k to 91 instead of 9.1 the resulting period is 0.93, much closer to reality.

Have I botched up the units along the way or what have I done wrong?

I'd be very greatful for help.

On the calculation of the natural frequency, what units does "m" have? What were the units of the "2" that you put into the numerator in side the square root?
 
the unit M is in Newtons, and its for measuring the oscilliation of the spring with a spring constant of 9.2 when its weighed down with 2 Newtons
 
I believe I´ve found a solution, by converting the unit m from Newtons to kg it looks more correct. Sorry for the inconvenience!
 
squashen said:
the unit M is in Newtons, and its for measuring the oscilliation of the spring with a spring constant of 9.2 when its weighed down with 2 Newtons

Are you sure?

t has what units? sec ? right?

What units do you get for "t" when you use M with units of Newtons?
 
squashen said:
I believe I´ve found a solution, by converting the unit m from Newtons to kg it looks more correct. Sorry for the inconvenience!
Yup! "m" is the mass of the bob in kg. Newtons are units for the force that the bob exerts. F = m*g

This is why it is always a good idea to work with units on your numbers. You would have seen that you got nonsense units for the period of oscillation if you had kept units of "m" and "k".
 
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