Light, reflection & shadows
Take your time. Show your thinking.
1. 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 2. 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 3. 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 4. Why do people often wear light-coloured or white clothing in hot sunny weather: white surfaces reflect most sunlight and stay cooler, or white absorbs all heat?
Light Ray (Straight Line) · Angle i = Angle r 5. 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 6. In which medium does light travel fastest: in a vacuum (space) or in diamond?
Light Ray (Straight Line) · Angle i = Angle r 7. 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 8. 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 9. 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 10. 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 11. 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 12. 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