Photo AI
A student carried out an experiment to investigate how the fundamental frequency of a stretched string changes with length - Leaving Cert Physics - Question 3 - 2020
Question 3
A student carried out an experiment to investigate how the fundamental frequency of a stretched string changes with length. (i) Draw a labelled diagram of the appar... show full transcript
Worked Solution & Example Answer:A student carried out an experiment to investigate how the fundamental frequency of a stretched string changes with length - Leaving Cert Physics - Question 3 - 2020
Step 1
Draw a labelled diagram of the apparatus used in this experiment.
Answer
To draw the diagram, include the following components:
- String: Represented as a long horizontal line.
- Tuning Forks or Frequency Generator: Show these beside the string, indicating their role in producing sound at specific frequencies.
- Bridge: Indicate where the string is supported at two points.
- Measuring Device: A ruler or similar device for measuring the length of the string, with labels to specify its purpose.
- Paper Rider/Magnet: This can represent the part detecting resonance, located on the string.
- Label each part clearly along with arrows to indicate connections.
Step 2
On your diagram, indicate and label the length measured by the student.
Answer
On the diagram, use a dashed line to highlight the section of the string between the two bridges. Label this length as 'L' to represent the distance being measured. This indicates the length of the string that is effectively vibrating.
Step 3
Step 4
Step 5
The length between the bridges is adjusted until resonance occurs. Describe how the student knew that resonance had occurred.
Answer
The student knew that resonance had occurred when:
- The amplitude of the string's vibrations increased significantly, indicating that energy was being effectively transferred.
- They may have noticed a stronger sound output when the length was adjusted appropriately.
Step 6
State the relationship between the resonance frequency and the length.
Answer
The relationship between the resonance frequency, denoted as , and the length, denoted as , is inversely proportional, as expressed by the equation: f ext{ is inversely proportional to the length } L: rac{1}{f} \\propto L This implies that as the length of the string increases, the fundamental frequency decreases, leading to lower pitch sounds.