Light, reflection & shadows
Take your time. Show your thinking.
1. 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 2. 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 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 can sound NOT travel through the vacuum of outer space whereas light can: sound is a mechanical wave that needs vibrating particles, or space is too cold?
Light Ray (Straight Line) · Angle i = Angle r 5. According to the law of reflection on a flat plane mirror, how does the angle of reflection compare to the angle of incidence: they are equal, or the angle of reflection is twice as large?
Light Ray (Straight Line) · Angle i = Angle r 6. Which of these is a luminous object (emits its own light): the Sun or the Moon?
Light Ray (Straight Line) · Angle i = Angle r 7. 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 8. What type of lens is thicker in the middle than at the edges and brings parallel light rays together to a focal point: a convex (converging) lens or a concave lens?
Light Ray (Straight Line) · Angle i = Angle r 9. 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 10. What astronomical event occurs when Earth passes directly between the Sun and the Moon, casting Earth’s shadow onto the Moon: a lunar eclipse or a solar eclipse?
Light Ray (Straight Line) · Angle i = Angle r 11. What do we call the bending of a light ray when it passes at an angle from air into water or glass (due to a change in speed): refraction or absorption?
Light Ray (Straight Line) · Angle i = Angle r 12. 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