Light, reflection & shadows
Take your time. Show your thinking.
1. At what time of day are outdoor shadows cast by the Sun shortest: around midday (noon) when the Sun is highest in the sky, or at sunrise?
Light Ray (Straight Line) · Angle i = Angle r 2. In which medium does light travel fastest: in a vacuum (space) or in diamond?
Light Ray (Straight Line) · Angle i = Angle r 3. What optical instrument uses two mirrors angled at 45° inside a tube to let an observer see over obstacles: a periscope or a stethoscope?
Light Ray (Straight Line) · Angle i = Angle r 4. Why does an opaque object cast a dark shadow when placed in front of a torch: light travels in straight lines and cannot pass through the opaque object, or the object absorbs darkness?
Light Ray (Straight Line) · Angle i = Angle r 5. Why does a red apple appear red in white daylight: it reflects red light and absorbs other colours, or it absorbs only red light?
Light Ray (Straight Line) · Angle i = Angle r 6. Why does a straight pencil standing partly in a glass of water look bent at the water surface: refraction of light rays leaving the water, or the water bends the wood?
Light Ray (Straight Line) · Angle i = Angle r 7. How does light travel through a uniform medium such as air or vacuum: in straight lines, or in curved loops?
Light Ray (Straight Line) · Angle i = Angle r 8. What is the imaginary line drawn at 90° (perpendicular) to a mirror surface at the point where a light ray strikes called: the normal or the tangent?
Light Ray (Straight Line) · Angle i = Angle r 9. Which of these is a luminous object (emits its own light): the Sun or the Moon?
Light Ray (Straight Line) · Angle i = Angle r 10. If a light ray strikes a flat mirror at an angle of incidence of 35° to the normal, what is the angle of reflection: 35° or 55°?
Light Ray (Straight Line) · Angle i = Angle r 11. Does light require a material medium (like air) to travel, or can it travel through the vacuum of space?
Light Ray (Straight Line) · Angle i = Angle r 12. What happens to the size of an object’s shadow on a wall when the object is moved closer to the small light source: the shadow gets larger, or the shadow disappears?
Light Ray (Straight Line) · Angle i = Angle r