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a) Factorise: 2x^2-72, and hence b) find the y-intercept of the line with the equation: y=(2x^2-72)/(4x-24)

a) Take out the common factor, giving: 2(x 2 -36), idenitfy the difference of two squares and factoise accordingly, giving: 2(x-6)(x+6) b) you have the facotirse version of the top of the fraction from part ...
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Answered by Innis S. • Maths tutor
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In a lab a hydrogen spectral line is observed to have a wavelength of 656nm. This line is observed in a distance galaxy to have a wavelength of 661nm, what is the recessional velocity of the galaxy?

This question is dealing with phenomena of Redshift, where wavelengths are shifted due to movement between observer and event. The key information to extract from the question is we have a rest wavelength, a...
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Answered by Jamie M. • Physics tutor
6945 Views

Describe how animals survive adverse weather conditions

One method of doing this is dormancy. Some animals spend a period of their life cycle dormant in order to lower their metabolic expenditure in conditions which would otherwise require high energy to survive....
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Answered by Jenni M. • Biology tutor
2681 Views

An exoplanet of mass 1.36x10^26 kg is orbiting a star of mass 3.2x10^31 kg at a distance of 1 AU. What is the magnitude of the gravitational force between the two?

We use Newtons equation for gravitational force. F=GMm/r 2 .1 AU is the mean distance at which the Earth orbits the Sun, taken to be: 1.49x10 11 m.Substituting in the numbers we find the magnitude of the for...
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Answered by Rory C. • Physics tutor
2811 Views

Explain the difference between elastic and inelastic collisions.

In all collisions, provided there are no external forces, momentum is conserved. This is the law of conservation of momentum. However, kinetic energy is not conserved in all collisions. An inelastic collisio...
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Answered by Ellie E. • Physics tutor
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