Homework Statement
http://img522.imageshack.us/img522/9016/circuitsel3.jpg
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Basically I need to find the brightness of the labelled lamps relative to the original lamp.
It is lamps c&d and g&h which are causing me the most trouble...
Homework Statement
http://img120.imageshack.us/img120/3743/physicsquestionnb9.jpg
http://g.imageshack.us/img120/physicsquestionnb9.jpg/1/
The Attempt at a Solution
I'm trying this problem and I'm really not sure if my answers are correct at all.
For part a) I get the kinetic...
For the first two parts of the question I simply used some symmetry to get the lines meeting the mirror at the correct angle. However for part c) whilst I know roughly what it should look like the angles aren't very accurate. Is there any simple method like the use of symmetry to draw lines at...
thanks for the reply.
I was working through your solution and knowing the context of the question, thought it seemed a little too complicated.
What I eventually found is that if you draw a line from the centre to a corner of the triangle, and another line from the centre to the tangent, you...
I'm having trouble with this question. For the first part I am guessing that the radius is 2 times larger for the bigger circle and therefore its area is four times as large, but I can't seem to prove that the radius is twice as large.I'd appreciate it if anyone could help me out on this question
Thanks for the reply, following your method I ended up with \frac{3}{8}+\frac{1}{2}cos2x+\frac{1}{4}cos4x
Just out of interest, if I were to square cos2x would I have to use the knowledge given in the question or does it equal something obvious?
Hi, I get stuck on the 3rd part of this question:
(i) Draw sketches of the functions sin x and sin^2x over the range -360<x<360.
(ii) Explain why, for the range 0 < x < 90=2, sin x is smaller than tan x.
(iii) Using the equality cos^2x=\frac{1}{2}(1+cos2x) or otherwise, express
cos^4xin...
After the hour hand has passed 8 on your watch, when will the minute hand and the hour hand be pointing in exactly opposite directions?
I did initially try formulating equations based on the change in the angle of the hour hand after x minutes, but it doesn't seem to be taking me anywhere...
Im wondering what made everyone eventually come to the decision that they wanted a degree in physics. I'm sure the fact that its a versatile and well respected degree was one of the factors but what got you into the whole subject?
Hi could someone explain what determines the amount of current going through each branch in a parallel cicuit. Does it just depend on the amount of resistance in each branch?
Im not looking for a complex explanation, but just the basic idea
Hi, could someone please tell me the circumstances under which you can divide a quadratic by the variable?
e.g. x^2 - (15/2)x = 0. I know I'd usually have to go through the whole factorisation/formula process and get more than one answer for x, but if I know that x is positive am I able to...
Homework Statement
A sequence of terms U1, U2, U3, ... is defined by Un = 5n + 20
If the sum of the first N terms of the sequence defined above equals the sum of the first kN natural numbers, show that:
N = 45 - k / k^2 - 5
Homework Equations
Sum of first N natural numbers =...
I know that molecules have kinetic and potential energy to make up internal energy. When the temperature of an object increases, the internal energy increases.
When the kinetic energy doubles, the temperature doubles as KE is directly proportional to the kelvin temperature. Does this mean...
"two circles of radii 5cm and 12cm are drawn, partly overlapping. Their centres are 13cm apart. Find the area common to the 2 circles"
I'm not quite sure how to do this. I think I am meant to be using the area of sector as if I draw a line down the middle of the area formed I can use the...