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Megapode birds open and close the air vents of the nest at different times of the day. Suggest reasons why it is necessary to open and close the air vents.

There are a number of reasons why it is necessary to open and close the air vents. These include; allowing oxygen in, which is also necessary for respiration and allowing heat to escape. Closing the ai...

Answered by Davina R. • Biology tutor

13428 Views

y is proportional to x^2. When y is 75, x is 5. Find a formula for y in terms of x

y is proportional to x² so this means y = A*x² for some constant A.

When y = 75, x = 5. Put these values in the formula above to find A:

75 = A*25

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Answered by Thomas M. • Maths tutor

5882 Views

Differentiate 4x^2 + 2ln3x + e^x

To differentiate x² you bring the power of x down, then reduce the power of x by 1, so d/dx(x²) = 2x¹

ln3x differentiates to (d/dx(3x))/3x = 3/3x = 1/x

Answered by Thomas M. • Maths tutor

7969 Views

Describe the photoelectric effect.

If we give a peice of gold negative charge and shine long wave, low frequency, electro-magnetic (E-M) radiation on it (for example radio waves) absolutely nothing will happen.

If you star...

Answered by Umar S. • Physics tutor

4599 Views

What is diffusion?

For the exams, the definition you will need to know is that "diffusion is the net movement of a substance from an area of high concentration to an area of low concentration, down a diffusion gradi...

Answered by Emily R. • Biology tutor

7302 Views