Plane mirrors and the law of reflection
Grade 11 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
A beam reflects off a flat mirror. Ari turns the mirror 6° about its hinge while the incoming beam stays put. By how many degrees does the reflected beam turn?
A beam reflects off a flat mirror. Bo turns the mirror 2.5° about its hinge while the incoming beam stays put. By how many degrees does the reflected beam turn?
A beam reflects off a flat mirror. Esme turns the mirror 12° about its hinge while the incoming beam stays put. By how many degrees does the reflected beam turn?
Jun measures 100° between a beam and its reflection off a flat mirror. What angle does the incoming beam make with the mirror's surface?
- 130°: the supplement of the 50° from the normal, 180° − 50°
- 40°: 50° from the normal, so 40° from the surface
- 80°: the supplement of the 100° between the beams, 180° − 100°
- 50°: half of the 100° between the beams, which is from the normal
The incoming and reflected beams at a flat mirror are at right angles to each other. What angle does the incoming beam make with the mirror's surface, Kira?
- 90°: the full angle between the two beams, not half of it
- 45°: each beam is 45° from the surface too
- 22.5°: half of the 45° that each beam makes with the normal
- 135°: the supplement of the 45° from the normal, 180° − 45°
A beam meets a mirror 35° from the normal. Luz tilts the mirror so it meets the beam 50° from the normal. How does the angle between the rays change?
- It grows from 35° to 50°, as if the rays were 35° and 50° apart
- It grows by 15°, the change in the angle from the normal
- It grows from 70° to 130°, as if the rays were 180° − 50° apart
- It grows from 70° to 100°, a gain of 30°
A lamp stays still in front of a plane mirror. Milo slides the mirror 0.5 m toward the lamp. How far does the lamp's image move?
- 0.5 m toward the lamp, the same distance the mirror moved
- 0.25 m toward the lamp, half of the mirror's own move
- 1.0 m toward the lamp, twice as far as the mirror moved
- 0 m, because the lamp did not move, so its image stays put
An arrow card in front of a plane mirror points straight at the mirror. Pia looks at its image. Which way does the image arrow point?
- Away from the mirror, the same way as the card's own arrow
- Sideways, because the mirror swaps left and right
- Nowhere, because a virtual image has no direction
- Toward the mirror, so the two arrows point at each other
Ren puts a white screen where a plane mirror's image appears, behind the glass. Why does no image show on the screen?
- No light goes there; it only seems to come from that spot
- The mirror is too smooth to send any light to that spot behind it
- The glass takes in the light before it reaches the screen
- The image is too dim to show up on a plain white screen
A 0.3 m tall lamp stands 3 m in front of a plane mirror. How tall is its image, and how far is it from the lamp, Tala?
- 0.3 m tall, 3 m from the lamp
- 0.15 m tall, 6 m from the lamp
- 0.6 m tall, 6 m from the lamp
- 0.3 m tall, 6 m from the lamp