Paper 3 physics !! get help here :)

[Osmix1995]

guys paper 3 physics is just around the corner!!
so let us help each other post notes and important things you think we should know

i will be the first one to ASK for help

i am very bad in moments ( you know the pivot thingy ) yeah i am clueless about this topic help will be appreciated

 

[Hamzeh S]

Cie or Edexcel ?

 

[gasserghoneim]

cie

 

[Hamzeh S]

Post any doubt and i will be happy to answer you

 

[gasserghoneim]

if u hv any notes can u please attach them i will be thankful if u did so

 

[Yousif Mukkhtar]

if u hv any notes can u please attach them i will be thankful if u did so

Here:
http://www.xtremepapers.com/community/threads/physics-guide.14933/

 

[gasserghoneim]

thnx u so much

 

[Osmix1995]

Post any doubt and i will be happy to answer you

me can you help me in the moments (pivot thingy?)

 

[Hamzeh S]

Sure What do you need ?

me can you help me in the moments (pivot thingy?)

 

[Osmix1995]

everything about that topic how you calculate it? what are special formulas for it? what is the principle?

 

[Hamzeh S]

Well the moment is equal to the Distance from the Pivot or center multiplied by the force or weight of the object

and clockwise moment is equal to anti-clockwise moment Because the object is always equilbream in the questions

so if we got an object which is 5 cm away from the pivot and its force or weight is 10 N (clockwise)
its moment is 50 now if he ask to find the force of the other weight which is acting in the opposite direction (anti-clockwise) and its distance from the pivot is 4 cm

you use the formula which is 50 = 4 x F
F = 50/4 F= 12.5 Newetons

Sometimes he ask find the force exterted by the pivot
you just need to find the force acting downward like the weight 10 N and 12.5 N and find any force acting upward sometimes its the spring pulling the ruler and you just need to find the force needed to cancel the effect of 10 and 12.5 downwards for example you got 20 N acting downwards and 5 N acting upward the force exerted is 15 N

 

[Hamzeh S]

Oh and for an object to be equalibream forces in the opposite direction must be equal and clockwise moment is equal to anti-clockwise moment just memorize them they are 2 points

 

[Osmix1995]

thank you bro you are waaaay better than our teacher

 

[Hamzeh S]

Haha no problem glad to help wow is your teacher that bad ? :S

 

[Osmix1995]

hahahahhahahahahaha he is does not even deserve to be a teacher he is good at physics but not teaching it

 

[Hamzeh S]

hahaha well good luck in your exam (Y)

 

[ygyh45]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s08_qp_3.pdf the first varient q8 part c can u plz explain it

 

[Hamzeh S]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s08_qp_3.pdf the first varient q8 part c can u plz explain it

First part the 60 W lamp are 3 so total power is 60 x3 which is 180 and subtract 15x3 from it it will give you 135 which power reduction
second part energy in the first condition was energy = 180 x 3600 ( 1 hour in seconds)
so energy at 180 W is 648,000 J
when using energy saving lamp its 15 x 3 (3 lamps ) x 3600 ( 1 hour in seconds ) = 162,000
subtract 648,000-162,000 its equal to 486,000 Joules

 

[gigglingstar]

Guys...I need help in radio activity and half life!!!!...can some one explain me in simple words!!!...and yes I also have a major problem with Fleming's left hand rule....I never got the right answers!!!

 

[ygyh45]

thank u sooooooooooooooo much