The use of analogies from everyday life can help better understanding of physics concepts - Scottish Highers Physics - Question 11 - 2017

The analogy of a car moving from a smooth road to sandy terrain can be insightful in understanding the concept of refraction of light.

Explanation of the Analogy

When a car moves from a smooth surface, like asphalt, to a rough surface, like sand, its speed decreases. This transition can be compared to how light behaves when it passes from a less dense medium (like air) into a more dense medium (like water or glass). In both scenarios, there's a change in speed due to varying resistances or densities.

Refraction Explained

In physics, refraction occurs as a wave crosses the boundary between two different media. For light, this change in velocity as it enters a new medium causes the light to change direction. Mathematically, this can be described by Snell's Law: $n_1 \sin(\theta_1) = n_2 \sin(\theta_2)$ where n is the refractive index of each medium and θ is the angle of incidence or refraction.

Conclusion

The analogy of the car effectively illustrates that as the speed of light decreases (similar to the car slowing down), it bends, just as the car might veer in a new direction when driving on sand. This can help in visualizing how light changes direction during refraction, promoting a deeper understanding of the underlying physics.