Karteikarten
Physics KS3 Y8
Karten in diesem Stapel (45)
- 1Why does a metal expand when heated?The particles move further away from each other by other particles vibrating and hitting each other
- 2What is the equation for pressure in solids?Pressure=Force/Area
- 3What is the equation for pressure in liquids?Force=Gravitational pull X Density X Depth
- 4Would there be more pressure exerted on a smaller facet or a larger facet and why?Smaller facet as more pressure is pushed on a smaller surface area however on a bigger facet, the concentration of the pressure extends and the force would be less spread out.
- 5What is a pascal (Pa)?A pascal is 1N/cm sq or 10,000N/m sq
- 6Why does a wide puddle evaporate more quickly than a deep puddle?This is because more particles are at the surface of the water and due to this more get pushed out at the same time
- 7Which would evaporate quicker and why? A) A puddle on a hot day B) A puddle on a cold dayA because on a hot day the particles move quicker and vibrate more and push each other quicker whereas on a normal day, the particles go at a slow constant pace.
- 8What is the difference between boiling and evaporating?Boiling is a very quick process and can only happen at a certain temperature whereas evaporation is a very slow process and can happen at many different temperatures.
- 9Do molecules vibrate quicker in hotter or colder metals and why?In a hotter metal because the molecules are hitting each other quicker.
- 10How does heat transfer with conduction?Heat transfers from a higher temperature to a lower temperature
- 11Why are solids better heat conductors than liquids and liquids than gases?Solids have a stronger bond and liquids and gases have weaker bonds
- 12Why does hot air rise and why doesn't cold air rise?It is less dense than cold because it has less particles per unit of volume.
- 13How does heat transfer?Heat transfers without movement or presence of particles/matter.
- 14What is thermal energy transferred by?Thermal energy is transferred by light
(Electromagnetic waves) called infrared. - 15What does a vacuum flask do?It stops heat transfers from higher to lower temperatures.
- 16How does a vacuum flask stop heat transfers?The insulators reduce heat loss by conduction.
The vacuum by convection and conduction.
Shiny glass reflects IR light and reduces heat losses by radiation.
The bung stops heat escape by convection - 17How do you stop heat loss in a home (5 methods)?Use double glazed windows
Use cavity wall insulation
Use fibreglass on the loft
Use carpets on the floor
Use a draught excluder by convection - 18Can energy be created?Energy can't be created or destroyed, but can only be transferred.
- 19What is the unit for energy and what does it stand for?J and this stands for joules
- 20What is the formula to find out the efficiency?Useful energy / Input energy X 100
- 21Does the sun rise in the east or the west?The east and it sets in the west
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- 23Is the sun higher in the summer or the winter and why?It is higher in the summer because the sun takes longer to set.
- 24Why is it hotter in the summer?This is because the sun is out longer and more heat is produced. This is because it is more concentrated on one area.
- 25What does it mean if a hemisphere is tilted towards the sun?It is summer and if it is tilted away then it is winter.
- 26Name all the equinoxes and solsticesSpring equinox- Around 21st March
Autumn equinox- Around 23rd September
Summer solstice- Around 21st June
Winter solstice- 22nd December - 27—
- 28What is an equinox and what is a solstice?Equinox- When day and night are the same length
Solstice- The longest or shortest day of the year - 29What is the approximate tilt of the earth?23.5 degrees
- 30What is a solar eclipse?When the moon comes between the earth and the sun blocking out the sun's rays.
- 31What is a lunar eclipse?When the moon moves into the umbra of the earth's shadow, so it can't be seen
- 32What are stars used for?Navigation
Farming
Astrology - 33What are light years?A unit of measurement used to determine how far stars and planets are away from each other
- 34What is a constellation?Patterns of stars in the sky
- 35What is a comet?A ball of dust and ice normally orbiting the sun, far beyond any planets.
- 36What is a moment?A turning effect of a force
- 37What is the formula for moments?M= F X D
Moment= Force X Perpendicular Distance - 38What happens at equilibrium?The sum of the anti clockwise moments are equal to the clockwise moments.
- 39What is the centre of mass of an object?A point where all the weight acts through
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- 41Is it better if the centre of mass is lower or higher?It is better if it is lower
- 42How do you make an object more stable?You put weights at the bottom, you widen the base or you make the object smaller in height and lower the centre of mass.
- 43What is stable equilibrium?When the weight falls within the base.
- 44What are machines?They make jobs easier
- 45How do machines work?They make the load closer to the pivot and therefore, when you apply a force further away from the load, less effort is needed.