Qualification > Reference Material
Physics P3 27/5/2010
The Golden Girl =D:
ya kimo ....7ato23d tiktab ma8al 6olu add 7ayatak kila .... lol
well i am tryin to be sarcastic (so not me :-X ) but i am proud of u and happy that u really want to help , if u need anythin in writting this ma8ala :P don't hesistate to ask for my help
(By the way i was kiddinn abt the first part)
cya
WARRIOR:
GENERAL PHYSICS[/color]\
not much i can do bout this but anway ill tell you what you need to okno
DENSITY - MASS/VOL Kg/m3 or g/cm3
Mass of regular solid : PLace onto a balance / Volume ( cube or cuboid ) Lxbxh /
NOTE : if u are given spring balance then the weight should be found first and then Divide by 10 !! to find mass
You have to know how to find the volume of irregerual solids ( the volume experimetn or displacement experiments )
You have to know difference between SCALAR QUANTITIES ADN VECTOR QUANTITIES
SCALAR HAS ONLY SIZE ex. temperature , mass , time
VECTOR HAS SIZE ( MAGNITUDE ) AND DIRECTION ex. velocity weight , acceleration , force
acclration = chage in velocity / time .. unit : m/s^2
Distance time graphs : very rare but you have to know what the gradients mean !!!
http://www.gcse.com/fm/dtg.htm this is the perfect site for this . JUST CLICK ON NEXT PAGE ( AWSOME :-X ::) ;D)
Speed time graphs
http://www.gcse.com/fm/stg.htm
TO CALCULATE THE DISTANCE : AREA UNDER GRAPH !! ( COULD BE TRIANGEL /TRAPEZIUM RECTANGLE )
Acceleration due to gravity ..
On the moon a hammer adn geather will fall at the same time Why? Caz there is no air resistance ! and theyll have the same constant acceleration but on earth there s air resistance !! which reduces the downward aceeleration of the featehr faster than it can do with the Hammer . And so hammer reachers first. Why is it easier to lift on the moon??
1. NO AIR RESISTANCE
2. WEIGHT IS LESS ON MOON W= MX G and g is < 10
remember force = M x a is the RESULTANT FORCE ! you have to know how to draw them E PAPER 3 JUNE 2006
You have to know the parachute jump
force down = weight or force of graivty force up = air resistance or drag ..you should know terminal velocity
http://www.yenka.com/freecontent/item.action?quick=55 <--- this is the graph on the left
One he steps out of plane the only force acting on him is weight and so there is a resultant force downwards !! and he accelerates downwards with an accelration of 10 m/s^2 . AS he gets faster he can feel air resitance pushin on him harder and harder and the upwards force due to drag increasers .SO this decreases the resultant force and so acceleration decreases !! UNITL
THE WEIGH FORCE = AIR RESISTANCE FORCE . And so no resultant force and so no accelraton ! and falls at a steady speed ( terminal velocity )
Then the parachute opens
Parachute has a large surface area and so more air resistance can act no w!!! and this creates a sudden rise in air resistance force and the jumper slows down . As he slows down the new air resistance force decreases and he falls down a steady speeed until he reaches the ground
CENTRIPETAL FORCE . ( force acting on any object moving in a circle )
Acceleration and constant speed :O :O
When an object is moving in circele and a const. peed its direction is changing constantly !!! This means velocity is also changing and so it is accelrating thought its speed is constand
REMEMBER ACCELRATION IS A VECTOR QUANNITTIY AND AND SPEED IS SCALAER
VECTOR = MAGNITUD + DIRECTION MAGNITUDE ONLY
Centripetal force in spring is cUSE BY TENSION . IN ROAD IS CAUSED BY FRICTION BETWN ROAD AND TIRES . IN SATELTIE IS CASUED BY GRAVITY .
When there is not enough friction / tension / gravity there will not be enough centripetal fore to keep car movin in a circle and will fly of in a TANGENT .
EQUILIBRIUM !
moment = F x D ( D IS DISTANCE FROM PIVOT ! )
for a pivot to be balanced there should be NO RESULTANT MOMENT = ANTI CLOCKISE MOMENT = CLOCK WISE MOMENT
NO RESULTANT FORCE = UPWARD FORCE = DWNWARD FORCE
remember . The longer the distance from the piVOT the less the FORCE IS NEEDED CHECK THE FORUMLA !!
you have to know centre of gravity .
the lower the centre of gravity the more stable / the wider teh base the more stable of movement
Type of energy
NUCLEAR ENRGY FISSION AND FUSION .. ENERGY RELEASD BY SUN IS FUSION
KINETIC ENERGY = Mv^2 / 2 ernegy
G.P.E= energy of height . Mgh
note
When an object falsl free under graavity its g..e decreases a its getting lower and its K.E is getting faster . The total energy ( KE + GPE ) stays the same since no energy lost AND SO G.P.E AT TOP = K.E AT BOTTOM ( JUNE 2004 QUESTION 2 )
Strain energy = when someting is bent or strechted ... etc
Effceincy = Useful Energy out / total enrgy in X 100% ( JUNE 2008 QUESITON 2 )
WORD DONE = F X D
POWER IS THE RATE OF WORK DONE THREFORE POWER - WORK DONW / TIME
Pressure = FORCE / AREA ( pascales pa ) or N/m^2
Pressure in liquids : Pgh
pressure acts in all directions and thats why it is equal around an object.
MANOMETER ( TO MEASURE GAS PRESSURE ) why water is used not mercury ?
BAROMETER ( TO MEASURE AIR PRESUR ) why mercury is use not warer? measured in mm of mercury
SPRINGS .
HOOKE'S LAW
F= kX
K = SPRING CONSTANT N/cm
^ is defined as how much force is needed to stetch the spring by 1 cm and findng tht u can find all forces and all extensions and work them out .
The law sttes that the extension is directly proportional to the tload . and u can see that from the formula
The spring can extend up to a limit . If more force is appplied the spring breaks . This limit is called elastic limit or limit of proportionality
YOU SHOULD KNO THE EXXTENTIONS OVER FORCE GRAPH
you shuld know how the ticekr timer works
The Golden Girl =D:
--- Quote from: Kimo Jesus on May 19, 2010, 02:31:07 pm ---lol thats really encouraging thx :P
--- End quote ---
no probs ::) lol.....nah seriously abt the helpin thing , i am really willing to help (iza fadya :P )
Adzel:
--- Quote from: Kimo Jesus on May 19, 2010, 07:45:57 am ---
* By induction ( complicated process will be studied later ). Pieces of iron( permanent) or steel ( temporary ) become induced magnets when you place them near magnet.
--- End quote ---
I think its the other way round... :-\
WARRIOR:
oopsy daizy
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