Karteikarten
Physics Revsion
Karten in diesem Stapel (16)
- 1Infrared radiation is energy transfer by electromagnetic waves. All objects emit infrared radiation.The hotter an object is, the more infrared radiation it emits in a given time
- 2Summary Questions How can you tell if an electric iron is hot without touching it?Put your hand near it to feel the heat radiating. Your hand will sense the heat to tell you its hot.
- 3Explain why penguins huddle together to keep warmPenguin are warm-blooded and they can regulate their body temperature. Penguins emit infra-red radiation naturally (as do all warm-blooded bodies).
The penguin at the centre of the huddled mass will be warmer than a penguin at the outer edges. The effect of the bodies is to create a wind-break, and magnify the effects of the heat generated at the centre. This will mean that penguins on the outer edges of the huddle will become warm on one side, and colder on the exposed side - so penguins on the outside turn their bodies to ensure they stay warm all over. - 4Investigation to model the effects of penguins huddling togetherPut a bunch of beakers with hot water around another beaker with hot water, and separately just place a beaker with the same hot water but no other beakers near it, and measure the temperature of the surrounded one and the isolated one and see which one stays warmer longer.
- 5Dark, matt surfaces emit more infrared radiation than light, shiny surfaces.Dark, matt surfaces absorb more infrared radiation than light shiny surfaces.
why? - 6A matt surface has lots of cavities. the radiation reflected from the matt surface hits the surface again. The radiation reflected from the the shiny surface travels away from the surface.Diagram
- 7Why does ice on a road melt faster in sunshine if sand is sand is sprinkled on it?Because sand heats up quicker than ice. Sand can melt ice if it is heated naturally from the sun or a warm temperature--just like any other substance that is warmer than ice.
- 8Why are solar heating panels painted matt black?It makes the panels more efficient as it absorbing as much radiation as possible and so heats up water quickly.
- 9A black car and a metallic sliver car are parked next to each other on a sunny day. Why does the temperature inside the black car rise more quickly than the temperature inside the sliver car?This is because dark, matt surfaces absorb more radiation than light shiny surfaces. Dark matt surfaces have cavities and therefore the reflected radiation hits the surface again while the light shiny surface has a smooth surface and therefore reflects the radiation away from the surface.
- 10States of matterSolids have no flow, a fixed shape, a fixed volume and a much higher density than a gas.
Liquids flow, fits containers shape (doesn't have a fixed shape), fixed volume and a much higher density than a gas.
Gas flows, fills container (no fixed shape), volume can be changed (no fixed volume) and a low density compared to a liquid or a solid. - 11When an ice cube melts what happens to its shape? It looses its fixed shape.
- 12What changes of state occurs when hailstones form?Solidifying or freezing
- 13The kinetic theory of matter.The particles in a solid are held next to each other in fixed positions. They vibrate about their fixed positions so the solid keeps its own shape.
- 14The particles in a liquid are in contact with each other. They move about at random. So a liquid doesn't have its own shape and it can flow.The particles in a gas move about at random much faster. They are much further apart from each other than in a liquid. So the density of the gas is much less than that of a solid.
- 15The particles in solids, liquids and gases have different amounts of energy. In general, the particles in a gas have more energy than those in a liquid, which have more energy than those in a solid.
- 16State the scientific word for each of the following: a mist appears on the inside of a window in a bus filled with people - condensationSteam is produced from the surface of the water in a pan when the water is heated before it boils - evaporation
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- Karteikarten am Physics Revsion, erstellt von aj02firestar am 16/02/2015.
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