Light, reflection & shadows
Take your time. Show your thinking.
1. Which of these is a luminous object (emits its own light): the Sun or the Moon?
Light Ray (Straight Line) · Angle i = Angle r 2. Why does a smooth mirror form a clear image while white paper does not: specular reflection vs diffuse scattering, or paper absorbs all light?
Light Ray (Straight Line) · Angle i = Angle r 3. How do we see a non-luminous object such as a printed book page: light from a source reflects off the page into our eyes, or our eyes send out beams?
Light Ray (Straight Line) · Angle i = Angle r 4. 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 5. Which part of the human eye is the dark circular opening at the centre of the iris that lets light enter: the pupil or the eyebrow?
Light Ray (Straight Line) · Angle i = Angle r 6. 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 7. In which medium does light travel fastest: in a vacuum (space) or in diamond?
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. 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 10. 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 11. 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 12. 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