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Describe and explain the differences between arteries and veins.

A rteries carry blood a way from the heart, whereas veins carry blood back towards the heart.Arteries have much thicker muscular walls in comparison to veins, as they need to carry blood at high pressure fro...
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Explain the process of speciation

Geographic isolation occurs so the population is separated and the two groups cannot interbreed. Variation due to mutation arises in the separate populations leading to different alleles becoming dominant an...
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Answered by Maria W. • Biology tutor
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A car driver has to make an emergency stop. The braking distance depends on the speed of the car. For the same braking force, what happens to the braking distance if the speed doubles?

For a situation like this it is best to think of the energy of the car!The car has a kinetic energy = 1/2mv 2 so if the speed has doubled the new kinetic energy of the car will be 1/2m(2v) 2 meaning the kine...
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Answered by Alice D. • Physics tutor
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A kettle boils 0.6kg of water. After some time the temperature of the water has decreased to 83 degrees. The specific heat capacity of water is 4200J/kg. Calculate the energy transferred to the surroundings.

The variables we are given are mass (m), time (t), temperate CHANGE (delta T) and SHC (c) and we are asked for energy. Think of the equations for energy we know: mgh, 1/2mv 2 , mcdeltaT...the first two energ...
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Answered by Alice D. • Physics tutor
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How do I begin a composition? How do I score top marks in my coursework?

Composition can often seem a daunting task, and many GCSE students simply do not know how where to begin. In truth, GCSE composition can be broken down into manageable, methodical steps. Examiners are lookin...
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Answered by Patrick D. • Music tutor
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