Year 8 Light Worksheet - Intermediate

Year 8 Light worksheet for Year 8 (Key Stage 3 / Year 7-9 (Ages 11-14)). Intermediate level science practice, aligned to the UK National Curriculum. Print-ready with answer key included.

Science•Key Stage 3 / Year 7-9 (Ages 11-14)•Lightintermediate

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Light in Action: Seeing, Reflecting and Refracting

Year 8 Science | Ages 12–13 | Intermediate

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Instructions: Work through the activities in order, showing clear working for calculations and using scientific vocabulary in explanations. Use the information printed in each activity; answers should be concise but give a reason where asked.

Light Travels in Straight Lines

Use the model of straight-line light rays to explain each situation. Include the word *ray* or *shadow* where it helps, and give a clear reason for each answer.

1. A torch shines towards a screen, but an opaque card is placed between them. Explain why a shadow forms on the screen. [2 marks]

2. A pinhole camera forms an upside-down image of a candle. Explain how straight-line travel of light causes the image to be inverted. [2 marks]

3. A narrow beam passes through three small holes in cards. The beam reaches the detector only when all three holes are aligned. What does this show about how light travels? [1 mark]

4. A book is hidden from a person behind a solid wall. Explain why the person cannot see the book, even though the room is lit. [2 marks]

Reflection and Refraction

Choose the most accurate answer for each question. Think about what happens to light at a surface or when it enters a different material.

1. A ray strikes a plane mirror at an angle of incidence of 35°. What is its angle of reflection? [1 mark]

2. Which description best explains regular reflection from a smooth mirror? [1 mark]

3. A ray enters glass from air at an angle. Which change usually occurs as it enters the glass? [1 mark]

4. A straw appears bent where it enters water. What causes this appearance? [1 mark]

The Eye and How We See

Use the labelled eye diagram and your knowledge of vision. Match each numbered part to a label from the word bank, then answer the questions below.

Word Bank

LensCorneaIrisPupilOptic NerveRetina

5. Which eye part changes shape to help focus light from near or distant objects? [1 mark]

6. Where are light-sensitive cells that detect light found? [1 mark]

7. What carries electrical signals from the eye towards the brain? [1 mark]

Colour and Filters

Use the facts in each question to reason about coloured light. A coloured filter transmits some colours and absorbs others; assume ideal filters unless stated otherwise.

1. White light passes through a red filter. Which colour of light is transmitted? [1 mark]

2. White light passes through a blue filter. Which colour is mainly absorbed? [1 mark]

3. Red light shines on a green object. The object reflects green light but absorbs the light falling on it. What colour does it appear? [1 mark]

4. Red and green light shine together on a white screen. What colour do they make by mixing light? [1 mark]

5. A yellow object is viewed under blue light only. Explain why it may appear dark. [2 marks]

Light and Sound: Comparing Speeds

Read the data table carefully. Use the stated speeds for all calculations, give units, and round the final time to two significant figures where appropriate.

Wave	Speed in air (m/s)	Distance travelled
Light	300000000	300000 km
Sound	340	340 m
Sound	340	1.7 km

1. How long does light take to travel 300,000 km? Give your answer in seconds. [2 marks]

2. How long does sound take to travel 340 m? Give your answer in seconds. [2 marks]

3. A person sees a distant firework and hears it 5.0 seconds later. Estimate how far away it is, using the speed of sound in the table. [2 marks]

4. Why do you see a distant firework before you hear its bang? [2 marks]

Answer Key

Activity 1: 1. The card blocks light travelling in straight lines, so the region behind it receives little or no light and a shadow forms. ; 2. Rays from the top of the candle pass through the pinhole to the bottom of the screen, and rays from the bottom reach the top, so the image is inverted. ; 3. Light travels in straight lines. ; 4. The solid wall blocks the light rays from the book, so no light from the book reaches the person's eyes.

Activity 2: 1. 35° ; 2. Parallel rays reflect in one direction ; 3. It slows down and bends towards the normal ; 4. Refraction

Activity 3: 5. Lens ; 6. Retina ; 7. Optic Nerve

Activity 4: 1. Red ; 2. Red and green (all colours other than blue; accept red and green) ; 3. Black or very dark, because it reflects green light but no green light is shining on it ; 4. Yellow ; 5. It reflects yellow light, which includes red and green components, but the blue light provides neither; it absorbs the blue light and reflects very little, so it appears dark.

Activity 5: 1. 300,000 km = 300,000,000 m; time = distance ÷ speed = 300,000,000 ÷ 300,000,000 = 1 s. ; 2. 340 ÷ 340 = 1 s. ; 3. Distance = speed × time = 340 × 5.0 = 1,700 m = 1.7 km. ; 4. Light travels much faster than sound, so the light reaches the observer first.