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When do we add and when do we multiply probabilities?

We add probabilities when the corresponding events are alternatives, e.g. P(rolling a 4 on a pair of dice) = P(rolling a 1 and a 3) + P(rolling a 2 and a 2). These are mutually exclusive events which can't h...
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Answered by Liora W. • Maths tutor
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How does one calculate centripetal force?

Consider the standard equation for force, F = ma. In a centripetal system, the acceleration a is given by a = v^2/r. Plugging this in to the equation for force yields F = mv^2/r; hence to calculate centripet...
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Answered by Liora W. • Physics tutor
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What is meant by the different sectors of economies?

Economies are made up of three sectors; the primary sector, which involves extraction of raw materials (e.g. timber), the secondary sector, which is concerned with manufacturing (e.g. turning timber into cha...
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Answered by Liora W. • Economics tutor
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What do consumer and producer surplus represent?

Consumer surplus is the benefit to people who want to buy a certain good that comes from the good being cheaper than what the consumer would be willing to pay; in other words, it is the difference between th...
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Answered by Liora W. • Economics tutor
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What are the properties of electromagnetic waves?

EM waves invariantly travel at the speed of light, and can do so in a vacuum. They transfer energy from their source to the absorber. Some kinds of EM waves can be reflected and refracted. The spectrum of el...
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Answered by Liora W. • Physics tutor
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