Year 9 Science · Unit 4 · Lesson 6
Foundation Worksheet
Learning Goals
Match each term to its definition
Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.
| Term | Your answer | Definition |
|---|---|---|
| Compression | A. The perceived highness or lowness of a sound, determined by frequency | |
| Rarefaction | B. Sound waves with frequency above 20,000 Hz, inaudible to humans | |
| Pitch | C. A region in a longitudinal wave where particles are pushed close together (high pressure) | |
| Loudness | D. Sound waves with frequency below 20 Hz, inaudible to humans | |
| Ultrasound | E. A region in a longitudinal wave where particles are spread apart (low pressure) | |
| Infrasound | F. The perceived volume of a sound, determined by the amplitude of the wave |
Fill the gap
Choose the correct word from the word bank to complete the passage. Use each word once. Two words in the bank are not used.
When a guitar string is plucked, it creates a that disturbs the surrounding air. This disturbance travels as a wave through the air to your ear. Sound cannot travel through a because there are no particles to carry the pressure wave — it needs a . The frequency of the sound wave determines its : a fast vibration produces a high-pitched note. The of the wave determines how loud the sound is. Sound levels are measured in units called the .
1. A student claps their hands next to a brick wall in a park. They hear an echo 0.5 seconds later. The speed of sound is 340 m/s. Calculate the distance to the wall. (Hint: the sound travels to the wall and back.) Show your working.
2. Explain why astronauts in space cannot communicate by shouting to each other through their visors. Use the correct scientific term for the type of wave that sound is, and explain what it requires to travel.
Wrap Up
In one sentence, what was the main idea of this lesson?