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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 = ...

Answered by Kezia M. • Maths tutor

3808 Views

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 th...

Answered by Alex N. • Biology tutor

10491 Views

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(mv²).This can be rearranged such that, m = (2E_k)/v²we know from the question that E_k= 100 J and we know that v = 15 m/sso ...

Answered by Tutor19729 D. • Physics tutor

3001 Views

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...

Answered by Alex N. • Maths tutor

4967 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 f...

Answered by Emma G. • Physics tutor

14565 Views