# AQA Physics 3 revision notes

Some notes i made for my self on some on the Physics 3 topics i was weaker on, i think ive got most things covered, but, if you can tell me in a couple of weeks if not then thanks...

"If we are gonna perform Inception then we need imagination."  Do you love watching films? Check out this site, http://www.lovefilm.com/mbfcar4gq/visitor/sign_up_1.html

HideShow resource information
• Created by: MatthewJG
• Created on: 19-05-10 16:52

First 179 words of the document:

PHYSICS III
Moment of force = force x perp. Distance from pivot
m = m
Centrepetal force acts towards the centre of the orbit
Centrepetal accel. = v²/r
Force = mv²/r
Geostationary Satellites, good for tv/radio/phones because they
stay in the same place over the earth, 24h orbit, HIGH!!
Low Polar orbit, orbits in a few hours, good for spying, weather,
can circumnavigate globe in hours, LOW!!!
Covex LENSES------CONVERGE LIGHT mirror, diverge light
Concave------LIKE A CAVE (diverge light) mirror, converge light
Magnification = image height / object height
Right hand rule...... thumb in direction of current, fingers curl is
way of arrows.
Direction of current in coil, positive to
negative
Left hand motor rule..... 1st finger, north to south
Catapult field 2nd finger, current, into or out of page
3rd finger, motion, mov'mnt of wire
A diode in a generater stops the negative bit, LUMPY DC
Using lots of coils at different angles smooths out the dc

## Other pages in this set

### Page 2

Here's a taster:

PHYSICS III
Human hearing = 20Hz to 20,000Hz
Echos!!!.... Speed = distance/time REMEMBER TO DIVIDE BY 2
(there and back)
V(wave speed) = F(frequency) x (wave length)
Sound is fastest in a solid
Step up transformer has more coils on the second side
Life cycle of a Star.....
Clouds of Dust and Gas (as gravity acts, the force is turned
into thermal energy and temp. Rises.
Protostar
Hydrogen nuclei undergo NUCLEAR FUSION
NUCLEAR FUSION and gravity oppose each other to make