Recent content by Saxby

Question: Explain why it is necessary to use relatively low energy X-rays to produce an image of the breast. My answer: Currently x-rays energy levels used during mammograms have approximately a one in a million chance of inducing cancer, this means that approximately for every two-hundred...

Does any else wonder if they'll soon be able to build a 3D printer which prints 3D printers? Someone must of had that idea :smile:

I don't really know what you're doing with is vector thing. I believe the best way to solve this would be to find the total force in the direction along the 12N, and the total force perpendicular to it. Then use Pythagoras' theorem.

Great Britain, University of Kent, Canterbury Campus :smile:

Homework Statement Derive an expression for the energy required to separate to infinity an electric charge +e and a charge -e, their initial separation being d. Homework Equations F = (q1*q2)/(4∏ * ε0 * d2)The Attempt at a Solution Basically what I've done is first make q1= +e and q2= -e and...

Homework Statement Two space ships, each a hundred metres long when measured at rest, travel toward each other with a speed of 0.85c relative to the Earth. Homework Equations λ = 1 / √1 - (v2/c2) x' = λ(x - vt) L' = L / λ The Attempt at a Solution Well to be honest i may be...

Why did the chicken cross the road? Because the North Korean long range missiles can't reach that far

Planck's radiation law: "Act of desperation" Why did Max Planck refer to his own radiation law (http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=35774&fbodylongid=1696) as an act of desperation. Was it because it was only mathematical and that he didn't really understand why the...

Homework Statement A refrigerator operating in a Carnot cycle is used to create 273 K by abstracting heat from water at 273 K and giving out heat to a room at 300K. To produce 3 kg of ice it abstracts 1.0 * 106J of heat from the water. Calculate: (i) The amount of heat given out to the room...

Thanks guys, I talked to my teacher and i can safely conclude the answer is y(0,t)=Acos(10∏t)

Homework Statement You have the simple harmonic equation for a transverse wave which is y(x,t)=Acos(10∏t+5x), what is the wave function at the originThe Attempt at a Solution By "at the origin" does it mean where x=0 and t=0. Because it that case y=Acos0 and therefore y=A. Is that right?

What is the wave function of a simple harmonic wave? y(x,t)=Asin(ωt+kx)

Thanks for your help guys :)

Why do some wave equations use sinθ and others cosθ? Does it make a difference when calculating properties such as wavelength and wave number? For example: y(x,t) = Asin(ωt+kx) y(x,t) = Acos(ωt+kx)

Your answer above is wrong. It may help to tell you that the tension in that rope would only depend on the mass of B (and not A). Remember the tension in string is equal to the force with which gravity is pulling the mass down the slope.