Aqa Definition and 15 Threads

can anyone explain why the voltage reading is negative for the resistor over a time period , yet the capacitor reading always stays positive ? In AC generation the voltages goes from negative to positive, how exactly does this affect the circuit components voltages? I am not sure how AC affects...

I assumed that i had to take 5 time constants which would give the time taken to charge fully i assume then divide by 10 giving me a total number of readings of 34 , the answer is 6 yet they only used a single time constant to determine the number of readings? as this give me an answer of 68 or...

I understand how they arrived at the answer of 2Q , but i have a couple of questions on this. If one of the charges were negative for example how would the resultant potential be found then? at the middle point would i add the positive charges and subtracted the negative ? Also what would the...

If i were to take one point as my origin and draw the two momentum, one for the initial collestion and one going from the wall after, from the origin point, then drawing horizontally i would get the answer as B as the resultant? Should i assume that for any resultant vector the direction can...

The answer is f/square root 2 If F = 1/2l * square root ( Tension/ mass per unit length ) ---------> this becomes I am assuming 1/2l * square root ( length * Tension/ mass ) this would give an answer of F yet the answer is F/ square root (2)

A couple of questions on this. How would the sound get reflected back from the surface of the water? And therefore create a stationary wave would the sound not travel though the water at a faster speed then reflect back and intefere? Or does a small amount of the sound reflect back? Part B...

This question is a bit werid because would there be a resulatant electric potential equal to zero as we have a positive and negative charge in which case there's no neutral point. As E1-E2 , they have to be acting in oppostie directions , in this case would they be acting in the same direction.

The spring constant of a helical spring is 28 N mñ1. A 0.40 kg mass is suspended from the spring and set into simple harmonic motion of amplitude 60 mm. i use the equation 1/2 change in extension times by force where the force i assume is mass times by 9.8 but the mark scheme uses 1/2 kx ^2 and...

and Homework Statement Ok, so I am doing As physics at the moment and have been left confused by stationary waves. I have read that between adjacent nodes/ even numbers the phase difference is always 0 and between numbers of does it is pi radians. So in the attatched image why is my textbook...

Hi all - just a bit confused about an answer in the AQA AS Physics textbook: 'Explain why a photon of energy 2MeV could produce an electron - positron pair, but not a proton - antiproton pair' and the ANSWER is: 'The rest energy of an electron and a positron is less than 2MeV but...

Homework Statement http://www.xtremepapers.com/AQA/Human%20Biology/2004%20Jun/AQA-BYA2-W-QP-JUN04.pdf Look at Q1bii) "Give the DNA base sequence that codes for threonine" Homework Equations The Attempt at a Solution So the DNA base sequence that CODES is on the sense strand mRNA is...

Hi, I have my AS Maths exam on Monday and so I was looking at some previous papers and I couldn't do this question: The quadratic equation (k+1)x² + 12x + (k-4) = 0 has real roots (a) Show that k² - 3k - 40 ≤ 0 I don't even understand where to start so I was hoping you could help me...

Homework Statement Does anyone know what's on the 2009 AQA AS level practical paper the ESA one? Homework Equations Any The Attempt at a Solution I don't know any thing but i guess it could have be on mechanics.

(a) (i) Express \(\sqrt{48}\) in the form \(k\sqrt{3}\), where \(k\) is an integer. (1 mark) ...(ii) Simplify \(\displaystyle \frac{\sqrt{48}+2\sqrt{27}}{\sqrt{12}}\) giving your answer as an integer. (3 marks) (b) Express \(\displaystyle \frac{1-5\sqrt{5}}{3+\sqrt{5}}\) in the form...

[FONT=Times New Roman]1. The line \(AB\) has equation \(7x+3y=13\). [FONT=Times New Roman] [FONT=Times New Roman](a) Find the gradient of \(AB\). (2 marks) [FONT=Times New Roman] [FONT=Times New Roman](b) The point \(C\) has coordinates \((-1,3)\). [FONT=Times New Roman] (i) Find an...