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a) You area told that y is proportional to x2 and that when y = 75, x = 5. Find a formula for y in terms of x. y = x b) Find the value of y when x = 3. c) Find the value of x when y = 1200.

a) y is proportional to x^2, when x is 5, y is 75 Therefore: 75 = (something multiplied by) 5^2 75 = 3 x 25 Hence y = 3x^2 b) y = 3 multiplied by 3^2 = 27 c) 1200 = 3x^2 1200/3 = x^2 400 = x^2 Undo the squar...
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Answered by Kezia M. • Maths tutor
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Describe the changes at the cell membrane of a neuron during an action potential.

At rest the membrane potential is -70mV . This is due to the Na + /K + pump, which actively transports 3 Na + ions out of the cell for every 2 K + ions in. Therefore there is a net negative charge inside the...
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Answered by Alex N. • Biology tutor
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What is the mass of an object travelling at 15 m/s with a kinetic energy of 100 J?

Kinetic Energy (E k ) = 1/2(mv 2 ).This can be rearranged such that, m = (2E k )/v 2 we know from the question that E k = 100 J and we know that v = 15 m/sso plugging in the numbers, we get m = (2 x 100)/(15...
TD
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Dipen and Nisha are planning their wedding reception. Nisha says, “I want to invite 70 guests.” Dipen says, “If we invite one-fifth fewer guests, we will save more than £500” Is Dipen correct? (Taken from Nov 2014 AQA Unit 2)

Need to calculate two things in order to answer the question: 1) Total cost of Nisha's 70 guests. 2) Total cost of Dipen's 'one-fifth fewer' guests. For Nishen: Total cost = £40 * 70 minus the 5% reduction =...
AN
Answered by Alex N. • Maths tutor
6017 Views

What's the difference between distance and displacement

Distance is a scalar, meaning it only has a magnitude. Displacement is a vector, meaning that it has both magnitude and direction. For instance, distance can state that I am "x" metres away from a ...
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Answered by Emma G. • Physics tutor
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