Paper 2 - Waves

Question 1

What is the frequency range for human hearing?

Answer 1

20Hz - 20,000Hz

Question 2

Describe a practical to investigate the speed of sound in air?

Answer 2

• Person 1 and Person 2 stand 100 meters from each other (measured with a trundle wheel)
• Person 1 has 2 wooden blocks and Person 2 has a stopwatch
• When person 2 sees person 1 hit the blocks together, they start the stopwatch, when they hear the wooden blocks collide they stop it.
• Then use the equation s=d / t to work out average speed
• Repeat 3 times and take an average
• Repeat the experiment at different distances such as 120, 140, 160 and 180 meters

Question 3

How can an oscilloscope and microphone be used to display a sound wave?

Answer 3

• Microphone detects sound waves and turn them into an electrical signal
• Oscilloscope will display the electrical signal as a transverse wave with voltage plotted against time

Question 4

How does the pitch of a sound relate to frequency of vibration of the source?

Answer 4

-The higher pitch, the more oscillations per second
- Waves have a shorter wavelength
- Waves have a higher frequency

Question 5

How does the loudness of a sound relate to the amplitude of vibration of the source?

Answer 5

• The louder the sound, the larger the amplitude
• So the waves have a larger negative and positive amplitude