CP7 Factors affecting the Frequency of a Vibrating String Flashcards
What are the 3 methods?
Finding the effect of tension on the frequency
Finding the effect of μ (mass per unit length) on the frequency
Finding the effect of the length on frequency
How (Tension)?
Attach 10 grams to the end of the pulley
Switch on the transducer and increase the frequency until the first harmonic (half a wavelength)
increase mass and repeat process
plot graph of frequency against tension
Equipment used?
Singal generator
Oscilloscope
Transducer
Pulley
How (μ)?
Measure the mass and length of string
Find μ
Keep 10g (tension constant) mass on pulley and find the first harmonic
Change the mass per unit length
Plot frequency against μ
How (length)?
Constant tension
Change the length of the string and find the first harmonic each time
Plot graph of tension against length
Reducing uncertainty?
Use of oscilloscope
Make sure not to use heavier masses
Make sure that the time base is set to 1 wavelength
Longer string
Problems?
Uncertainty at nodes as they may be blurry
The signal generator needs time to stabilise before use
What is λ in this experiment?
λ = 2 x length of string
What formula is used for this experiment?
v = 𝑓λ = sqrt(T/μ)
What can be used to alter the length of the string?
Trianglur bridges
Safety hazards?
Stand may fall over so a counterweight is needed for an opposing moment
Wire snapping
Weights dropping
Major sources fo uncertainty?
