Light Travels in Straight Lines

Question 1

Sam holds a flashlight 30 cm from a white board. He places a cardboard cut‑out of a kite 10 cm in front of the flashlight so the kite blocks the light. The shadow that appears on the board has the same outline as the kite, only bigger. Which statement best explains why the shadow’s outline matches the kite’s shape?

Accepted Answer

Light travels in straight lines; the parts of the board that get no light are exactly those behind the kite, so the blocked region copies the kite’s outline.

Answer

The light spreads out, and the areas that receive less light take the shape of the kite.

Answer

Light bends around the edges of the kite, forming a shadow that matches the kite’s shape.

Answer

Because the flashlight is close to the board, the board reflects the kite’s shape like a mirror.

Question 2

Lena shines a flashlight toward a white screen. She holds a small opaque heart‑shaped cut‑out 8 cm in front of the flashlight, and the screen is 20 cm behind the cut‑out. Which statement correctly describes the shadow that appears on the screen?

Accepted Answer

The shadow will be a heart shape that looks exactly like the cut‑out but will be a little bigger because the light rays spread out after passing the cut‑out.

Answer

The shadow will be a heart shape that is the same size as the cut‑out, because light does not change the size of objects.

Answer

The shadow will be a heart shape that is flipped left‑to‑right, because the light reverses the image.

Answer

The shadow will be a blurry, fuzzy shape, because light bends around the edges of the cut‑out.

Question 3

A student shines a flashlight on a small toy dinosaur placed on a table and observes the shadow it casts on a wall. Which explanation best describes why the shadow has the same shape as the dinosaur?

Accepted Answer

Because light travels in straight lines, the dinosaur blocks the same pattern of light, so the shadow has the same outline as the dinosaur.

Answer

Because the dinosaur moves while the light is traveling, the shadow is stretched and has a different shape.

Answer

Because the light source is far away, the shadow is smaller than the dinosaur, so its shape changes.

Answer

Because light reflects off the dinosaur, the reflected light creates a shadow that is a mirror image of the dinosaur.

Try three questions

Lena shines a flashlight toward a white screen. She holds a small opaque heart‑shaped cut‑out 8 cm in front of the flashlight, and the screen is 20 cm behind the cut‑out. Which statement correctly describes the shadow that appears on the screen?

A student shines a flashlight on a small toy dinosaur placed on a table and observes the shadow it casts on a wall. Which explanation best describes why the shadow has the same shape as the dinosaur?

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