RP1: Stationary Waves On A String Flashcards
What is a stationary wave?
A wave that stores, but does not transfer, energy
How do stationary waves form on a piece of string?
Two waves with the same wavelength, travelling in opposite directions, interfere with each other. They undergo superposition and a stationary wave is formed
What is a node?
A point of no displacement on a standing wave
What is an antinode?
A point of maximum displacement on a standing wave
Describe the arrangement of nodes and antinodes when the string is vibrating at its fundamental frequency
One central antinode and a single node at each end
What piece of apparatus can be used to generate a wave in a piece of string?
A vibration generator driven by a signal generator
What piece of apparatus can be used to alter the length of string that is oscillating?
A bridge that can be moved along the length of the string
Why should the signal generator be operated for several minutes before use?
It needs time for the frequency to stabilise
In this experiment, the string is tied to a clamp stand. To carry out this experiment safely, what must you add to the stand?
A counterweight to stop the stand from toppling over
How does the length of the string affect the frequency of the first harmonic?
Inverse relationship - as string length increases, frequency decreases
How does the string’s mass per unit length affect the frequency of the first harmonic?
As mass per unit length increases, frequency decreases
How does the tension in the string affect the frequency of the first harmonic?
As tension increases, frequency increases
How can the tension in a string be varied?
By attaching a mass hanger to the end of it. As mass is added, tension increases
What safety precautions should be taken when using mass hangers?
Never stand directly underneath - if it falls it may cause injury. Place a padded bucket below
How can you measure the mass per unit length of a piece of string?
Measure the mass of the string using a balance and divide it by the string’s length
