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Figure 7 shows a tuning fork - Edexcel - GCSE Physics - Question 5 - 2018 - Paper 1
Question 5
Figure 7 shows a tuning fork. When the prongs of the tuning fork are struck, the prongs vibrate in the directions shown by the arrows on Figure 7. Describe how the ... show full transcript
Worked Solution & Example Answer:Figure 7 shows a tuning fork - Edexcel - GCSE Physics - Question 5 - 2018 - Paper 1
Step 1
Describe how the vibrating tuning fork causes a sound wave to travel through the air.
Answer
When the prongs of the tuning fork vibrate, they move back and forth rapidly. This movement creates areas of compression and rarefaction in the surrounding air. As the prongs move outward, they push air molecules away, causing a compression. When the prongs move back, they create a rarefaction as the air molecules are pulled back. These compressions and rarefactions propagate through the air as sound waves, allowing the sound to travel.
Step 6
Explain, in terms of speed, why the light behaves like this.
Answer
When light transitions between media of different densities, such as air and glass, its speed changes. In air, light travels faster than in glass due to the different refractive indices of the two materials. This change in speed causes the light to bend, resulting in a phenomenon called refraction. The bending of light at the boundary leads to the separation of colours, as different wavelengths of light are refracted at different angles.