Year 9 Science · Unit 4 · Lesson 10

Checkpoint 2 — Sound, EM Spectrum, Light

Foundation Worksheet

Name

Date

Class

Learning Goals

Define key terms from Lessons 6–9 covering sound, hearing, EM spectrum, and light.
Distinguish between types of sound (ultrasound, infrasound) and types of reflection.
Identify the properties and applications of electromagnetic waves and light interactions.

Warm Up

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
Ultrasound		A. A unit used to measure the intensity (loudness) of sound
Infrasound		B. The bending of light as it passes from one medium into another
Decibel		C. Sound above the upper limit of human hearing (above 20 000 Hz)
Cochlea		D. Reflection from a rough surface where light scatters in many directions
Specular reflection		E. Sound below the lower limit of human hearing (below 20 Hz)
Diffuse reflection		F. The snail-shaped inner ear structure that converts vibrations to nerve signals
Refraction		G. Mirror-like reflection from a smooth surface where parallel rays stay parallel
Total internal reflection		H. When light hits a boundary at an angle greater than the critical angle and reflects entirely back

Your Turn

Sort it!

Write each statement from the pool into the correct category box below.

Needs a medium to travel Travels at 3 × 10⁸ m/s in a vacuum Pitch is determined by frequency Radio waves have the longest wavelength Angle of incidence equals angle of reflection Can be longitudinal or transverse X-rays are used in medical imaging Occurs when light slows down entering a denser medium Loudness is determined by amplitude Gamma rays have the highest frequency Used in fibre optic cables Speed in steel is greater than speed in air

Sound Waves

EM Spectrum

Light Interactions

Show What You Know

1. State two differences between sound waves and electromagnetic waves. Include whether each type of wave needs a medium to travel.

Recall 2 marks

2. Name one application of ultrasound and one application of infrared radiation. For each, briefly explain why that type of wave is suitable.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?