Plane mirrors and the law of reflection
Grade 11 Science Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
Ari's drone flies straight at a wall mirror at 1 m/s. The mirror, on a cart, rolls toward the drone at 3 m/s. How fast does the drone approach its image?
Bo's drone flies straight at a wall mirror at 2 m/s. The mirror, on a cart, rolls toward the drone at 3 m/s. How fast does the drone approach its image?
Two mirrors meet at 90°. A beam meets the first at 25° to its surface, reflects, and hits the second. At what angle does it meet the second mirror's surface, Jun?
- 35°, using 90° − 55°
- 115°, the supplement of 65°
- 65°: 90° − 25° for surfaces at 90°
- 25°, the same as at the first mirror
A lamp sits between two hinged mirrors set 40° apart. How many images of the lamp does Kira's camera see?
- 7 images: 360° ÷ 40° − 2
- 9 images: 360° ÷ 40°, forgetting to remove the lamp itself
- 8 images: 360° ÷ 40° − 1
- 4 images: 180° ÷ 40°, rounded down
A lamp 3 m above a floor mirror sends light, with one bounce, to a sensor 2 m above the floor and 12 m away across it. How long is the light's path, Luz?
- 12 m: the distance across the floor
- 13 m: the straight line to the sensor's image, √(12² + 5²)
- 12.04 m: the straight line from the lamp to the sensor itself
- 17 m: 3 m + 2 m + 12 m
Read this first
Spot shift on a wall 5.0 m away (example data)
mirror turn (°) spot shift (cm) 2 35.0 4 70.3 6 106.3 Milo says the reflected beam turns by the same angle as the mirror. A 2° mirror turn moves the spot 35.0 cm on a wall 5.0 m away. Does the table support the claim?
- No: 35.0 cm over 5.0 m is about 4°, twice the 2° turn
- Yes: the shifts rise in steady steps, so both turn together
- Yes: 35.0 cm over 5.0 m is about 2°, the mirror's turn
- No: the beam turns 1° for each 2° of mirror turn
Pia says a plane mirror swaps left and right. Which reply is closest to the physics?
- Yes: it flips whatever is on the left over to the right
- Yes: it flips left-right and up-down in the same way
- No: it reverses front and back, which only looks like left-right
- No: its image is an exact copy facing the very same way
A beam must be turned through 30° by one flat mirror. Ren sets the mirror's surface at what angle to the incoming beam?
- 60°, twice the turn
- 75°: (180° − 30°) ÷ 2, mixing up turn and angle
- 30°, the turn itself
- 15°: the beam turns by twice that angle
Tala wants the same small mirror turn to move the spot 4 times as far on a wall. What should change?
- Put the wall 4 times as far from the mirror
- Use a mirror 4 times as large
- Use a brighter light source
- Put the wall 2 times as far from the mirror
A beam traveling east must be turned to travel north by one flat mirror. Along which line should Zee set the mirror's surface?
- Along the northeast–southwest line
- Along the east–west line, parallel to the beam
- Along the north–south line, parallel to the new direction
- Along the northwest–southeast line