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Physics P1-P3
Physics Revision
Question | Answer | ||
---|---|---|---|
Explain the difference between heat and temperature. What units are they measured in? | Temperature is a measure of how hot something is and heat is a measure of energy (on an absolute scale) | ||
Describe how a heat from an imersion heater is transferred throughout the water in a tank. What is this process called? | Convection - Water is heated and becomes less dense (it exands) and rises the warm water displaces the cool water and the cool water sinks the cool water then is heated and it continues (circulation of fluid) | ||
Explain what refraction is and how it can disrupt radio signals. | refraction is when the ray changes direction, it can disrupt radio signals because refraction can disrupt a signal by bending it AWAY from the reciever dish. | ||
Decribe how mircowave ovens cook food. | The mrcowaves penetrate a dew centimetres into the food before being absorbed by water moleules and increasing their kinetic energy. The energy is then conducted or convected to other parts. | ||
How might a volcanic eruption change the climate of the Earth? | when a volcano erupts alot of dust can shot up high into the atmosphere. the dust reflects radiation from the sun. less radiation gets trhough to earth, which cools down as a result | ||
Explain why sending data by optical fibres might be better than broadcasting it as a radio signal? | It can travel very fast and optical fibres are inside a cable so are very secure whereas radio waves can be intercepted very easily and can carry lots of infromation. |