Physics, Chemistry and Biology: Post your doubts here!

[ZainH]

Please can some one help me understanding saponification

I don't know what that is, it's not in my book :s

 

[semsemhosam]

really?! that's weird....i have physics at 10 AM and maths at 1300...:/

 

[za Shadow]

it is SORTED OUT , so it should be of the same resistance

SRY but what does SORTED OUT means anyway

 

[kainat husain]

okie fine i'll not pay attention for saponification! but i have a doubt in this physics
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
question 31 the answer is B. but i don't understand! please can some one help

 

[sara16]

ahhhhh....physics is driving me crazy........
can sum1 please help me out! i dont understand hw does variable resistor,sliding contact help in a circuit also what happens in solenoid and transformer ? and why is electrical energy is transmitted at high voltage in transformers?
please reply ASAP!

 

[kainat husain]

PLEASE HELP ME
i have a doubt in this physics
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
question 31 the answer is B. but i don't understand! please can some one help
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
question 32 please tell me how the concept is? the answer is b
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
question 34 the answer is a...but this one also i didnt get :/

 

[za Shadow]

PLEASE HELP ME
i have a doubt in this physics
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
question 31 the answer is B. but i don't understand! please can some one help
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
question 32 please tell me how the concept is? the answer is b
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
question 34 the answer is a...but this one also i didnt get :/

question 31 --> I've got the same doubt too
question 32 --> when the switch is open as u know the capacitor STORES electric charge so will still give out the stored electric charge even after the switch is open and the battery too it gives out voltage as it is the SOURCE of the voltage through out the circuit BUT the resistor doesn't store and is not the source of anything that's y its B
question 34 --> the current (electrons) move through the copper wire not the insulation. Second, when u make it thicker the wire there will be less friction between the copper wire and the electrons so there will be less heating effect

hope that helped

 

[sma786]

when your decreasing the volume and the mass of air in the cylinder is same means your compressing it , so the air molecules will have less space to move , so they hit the walls of the container more frequently increasing the pressure
hope that helps and best of luck

thanks alot .. i misunderstood the questn

 

[semsemhosam]

thanks alot .. i misunderstood the questn

ur welcome

 

[sma786]

ASALLAM O ALIKUM!
the answer is C because when volume decreases pressure increases they are inversely proportional.. and B is not the answer because The pressure of a fixed mass of gas in a cylinder is measured. The volume of the gas in the
cylinder is then slowly decreased.
So that's y its C
i hope you get it
best of lucky

thanks alot =]

 

[semsemhosam]

SRY but what does SORTED OUT means anyway

i don't kow how to say it so im just going to give an example , i have a basket full of apples , im sorting out the red apples , yellow and green ones , so i put the red apples together , the yellow together , and the green together , ok here is its meaning from the dictionary : "separate or classify into units"
hope u got the point & best of luck

 

[IGSCE.Geek.]

The topic momentum has been obsolete and is no longer in the syllabus. unless you are referring to moments of a force

 

[semsemhosam]

okie fine i'll not pay attention for saponification! but i have a doubt in this physics
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w07_qp_1.pdf
question 31 the answer is B. but i don't understand! please can some one help

because the 2 resistors are connected in series , so the total resistance of both resistors will be higher than the one resistor and the three resistors connected in parallel , and current is inversely propotional to resistance , so as the resistors connected in series have the greatest resistance , they will have the least current
hope u got it
best of luck with ur exams

 

[za Shadow]

i don't kow how to say it so im just going to give an example , i have a basket full of apples , im sorting out the red apples , yellow and green ones , so i put the red apples together , the yellow together , and the green together , ok here is its meaning from the dictionary : "separate or classify into units"
hope u got the point & best of luck

THANKS

 

[za Shadow]

i've got another problem
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s05_qp_1.pdf
q29 my answer was: C and the marking scheme's answer was: D but i don't know why

 

[za Shadow]

aaaahhhhhhhhhhhh plzzzzzzzzzz help
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w03_qp_1.pdf

Q1 why D Q3 why A Q5 why C Q8 why A Q14 why D Q16 why A Q17 why D Q26 why B Q39 why C

i am sooo worried exam in 2 days time plzzzzzzzzzzz help

 

[Hamzeh S]

aaaahhhhhhhhhhhh plzzzzzzzzzz help
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w03_qp_1.pdf

Q1 why D Q3 why A Q5 why C Q8 why A Q14 why D Q16 why A Q17 why D Q26 why B Q39 why C

i am sooo worried exam in 2 days time plzzzzzzzzzzz help

Well Q1 cause you dont need a large cylinder simple i mean if you have a normal sized measuring cylinder you just add water and measure the volume difference any volume of water can measure the volume not neccesarly to be large volume of water

Q3 because the car is still accelerating and it is at the slowest speed
Q 5 because they need to be equal so the object is at equilabriem clockwise moment = anti clock wise moment so same distance so the force must be equal or weight if x is larger it will fall because the anti clock wise moment is more than the clockwise moment

q8 Because for object to be at equilabream opposite forces must be equal
q14 Because all Particle move solid they vibrate in their position liquid they slide past each other gas and liquid (brownian motion)

q16 Because the first diagram shows gas particle and then they fell and became closer to each other so it became a liquid if it became solid they would be arranged and closer to each others
q17 because more thermal capacity means its not willing to lose or gain heat fast Less thermal capacity Gains and loses heat faster
q26 idk why but i just know it cant explain
q39 in the nucleas there is only protons and neutrons so its c

 

[semsemhosam]

THANKS

ur welcome

 

[semsemhosam]

i've got another problem
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s05_qp_1.pdf
q29 my answer was: C and the marking scheme's answer was: D but i don't know why

because u cannot connect the voltmeter with anything else in series ( cuz it has high resistance)
hope that helps and best of luck

 

[areebaization]

PHYSICS DIFFRACTION OF WATER WAVES!
Can some one explain that in detail pleaseeee?
I want to know that in the figures in question 19, when EACH of the figures are possible as in what width of the gap should be to make the direction of the water waves shown possible. And secondly, which ones are not possible? Link:
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w06_qp_1.pdf
I am waiting ppl I hope u get what my question is