Investigation into the variation of the frequency of station waves on a string with length, tension, and mass per unit of string Flashcards Preview

AS Physics Practical Revision > Investigation into the variation of the frequency of station waves on a string with length, tension, and mass per unit of string > Flashcards

Flashcards in Investigation into the variation of the frequency of station waves on a string with length, tension, and mass per unit of string Deck (12)
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1

What is used to create the vibrations?

a vibration generator, connected to a singal detector

2

What is used to secure

string is thread through the vibration generator to a retort stand

the retort stand is held by a counterweight

 

the other end of the string is held against a moveable bride

it is then attached to mass on a pulley clamped to the bench

3

What are the control measured?

  1. leave the signal generator on for 20 minutes, in order for the frequency to stabalise
  2. the ouput power should be turned up to a value which gives steady vibraation
  3. the bridge should be at the same height as the hole

4

What is the independant variable?

the length of the distance between the vibration generator and the position of the bridge

5

What is the dependent variable?

the freuquency of the resonations

6

how is the frequency found?

frequency of the signal generator from zero until the string resonates at its fundemental frequency

 

(node at each end and a central antinode)

7

How are the results made more reliable?

8

What graph is plotted?

1/f against length

9

What is the gradient?

should be a straight line through the origin

 

c = fλ = 2fL (at fundemental node) 

 

the gradient is 1 / fl 

 

so c is giv en by 2 / gradient in ms-1

10

What are the alternatives to this technique?

different masses hanging on the string

 

different thickness of string

 

to investigate the ffect of changing tension and mass of the string

11

How is speed found from tension and mass?

c = √ ( T / m )

 

m = mass per unit of length ( kgm-1)

12

What effect does doubling the fundemental frequency while keeping l, T and m constant?

causes teh string to resonate in its second harmonic

 

(nodes at either end, a central node, and two antinodes)