Light, reflection & shadows
Take your time. Show your thinking.
1. 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 2. 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 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. 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 5. Which light-sensitive layer at the back of the human eye detects focused light and sends signals to the brain via the optic nerve: the retina or the earlobe?
Light Ray (Straight Line) · Angle i = Angle r 6. 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 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 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 9. 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 10. 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 11. 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 12. 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