krit.club logo

Light and Shadows - Transparent Material

Grade 3Cambridge (IGCSE)

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

•

When light rays hit a transparent object, they continue to travel in a straight line through the material. This is why the image we see through glass is not blurry. If 100%100\% of light rays hit a perfectly transparent surface, nearly 100%100\% of those rays exit the other side.

📐Formulae

Transparent=Light passes through fully\text{Transparent} = \text{Light passes through fully}

Shadow Formation∝Amount of light blocked\text{Shadow Formation} \propto \text{Amount of light blocked}

Transparency≈Light OutLight In×100%\text{Transparency} \approx \frac{\text{Light Out}}{\text{Light In}} \times 100\%

💡Examples

Problem 1:

A scientist shines a beam of light at three different objects: a brick, a piece of frosted glass, and a clear window pane. Which object will not produce a dark shadow?

Solution:

The clear window pane.

Explanation:

The clear window pane is made of transparent material. Light passes through it rather than being blocked. A shadow is a dark area where light is blocked by an opaque object. Since the transparent window lets light through, no dark shadow is formed.

Problem 2:

Why can we see the fish inside a clean glass aquarium clearly?

Solution:

Because both the glass and the water are transparent.

Explanation:

Light reflects off the fish and travels through the water and the glass to reach our eyes. Because these materials are transparent, they do not scatter or block the light, allowing a clear image to form in our eyes.