Physics, Chemistry and Biology: Post your doubts here!

[Ahmedm96]

but whats a sinker?

some thing used to sink less dense materials in water

https://encrypted-tbn0.gstatic.com/...2BjqiLtJCC5IZd4gluDv3Dz7gbwvark_t1nPfxHXLKYSg

 

[sparsha.mehta]

physics doubt..

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w06_qp_3.pdf

Q. 1 b (iv).. thanks in advance

You might be knowing cork flotes in water so finding out volume can b a problem.in the experiment you can add a sinker insense a metal tht will make the cork sink so tht its volume is takn.first take out sinlers volume,then the cork and sinkers volume.subtract the sinker's volume frm this and get the answer

 

[nigga7]

question number 6,9 and 11 need the answers and explanation to them as well

 

[Nita Mahajan]

What type of questions generally come for organic chemistry ?? What all do we need to know?

 

[Nita Mahajan]

I have a physics doubt... hope u can solve it for me...!

A tsunami is a giant water wave. It may be caused by an earthquake below the ocean. Waves from a certain tsunami have a wavelength of 1.9*10^5 m and a speed of 240m/s. The shock wave from the earthquake travels at 2.5*10^3 m/s. The center of the earthquake is 6.0*10^5 m from the coast of a country. Calculate how much warning of the arrival of the tsunami at the coast if given by the earth tremor felt at the coast.

 

[sparsha.mehta]

What type of questions generally come for organic chemistry ?? What all do we need to know?

in ppr 3 all structural formulas r asked.........u neeed to all functional groups,all links,combustion of a named hydrcarbon.differenciation between addition and condensation polymerisation.drawing monomers and polymers.hope this is helpful........

 

[diamondsky]

question number 6,9 and 11 need the answers and explanation to them as well

6.a)For O: its a mirror so d image shud b approx. d same dist. on d right of d mirror as O is to d right
For P: P is between focus n lens, so virtual image is formed
b)i)If the rays do not actually converge but appear to come from the image point, the image is called virtual. it cannot b captured on a screen
ii) both r erect, ie. dey arent vertically inverted
iii)d image in d mirror is on d oder side bt fr d lens its on d same side

9.a) it is when a magnetic field is cut by a conductor and an e.m.f is generated
b)sumwhat lyk dis

c) when moving a magnet in and out of d solenoid, der is a deflection on d meter
d) move magnet faster
use a stronger magnet

11.a)a bit confusing
i. take d background radiation n record its value
ii. place d beta source n take d readin on d counter
iii. repeat with placin 1 sheet of Al each tym
iv. subtract back. radiation frm oder readings

b)count reduces as thickness increases n finally no b-particles can penetrate,ie. back. radiation value

 

[diamondsky]

I have a physics doubt... hope u can solve it for me...!

A tsunami is a giant water wave. It may be caused by an earthquake below the ocean. Waves from a certain tsunami have a wavelength of 1.9*10^5 m and a speed of 240m/s. The shock wave from the earthquake travels at 2.5*10^3 m/s. The center of the earthquake is 6.0*10^5 m from the coast of a country. Calculate how much warning of the arrival of the tsunami at the coast if given by the earth tremor felt at the coast.

time taken fr tremor:6 *10^5/2.5*10^3 = 240s
=>time fr tsunami = 6*10^5/240 = 2500s
warning tym = time fr tsunami - time fr tremor = 2500 - 240 = 2260s
i hope its correct

 

[sparsha.mehta]

whats isomers or i mean how to draw it ??

Thy r different forms af same element.in organic chemistry thy ask to draw isomers.so if they say...1-ol or ...1-ene u hv to show the carbo carbon souble bond first or last do for 2-ene the same way.
Hope this helped...

 

[ZohaibAsad]

Two draw isomers, you need to take these three things into account:

1- Position of a functional group
2- Changing the functional group using the given atoms
3- Changing the chain structure

That gives you at least three different isomers every time.

 

[Ahmed Nasser]

guys whats should be the valencies for the transition metals? i know that each element have different valences, but whats the valency that we should use in solving equations for example? as i remember they were 2 or 3 but silver is 1 ??

 

[sparsha.mehta]

guys whats should be the valencies for the transition metals? i know that each element have different valences, but whats the valency that we should use in solving equations for example? as i remember they were 2 or 3 but silver is 1 ??

For transition metals valency consider the roman numer in brackets as a valency..dont predict valency tht u hv read somewhere

 

[Ahmed Nasser]

thnx . sorry but how to calculate the Empirical Formula ??

 

[sparsha.mehta]

thnx . sorry but how to calculate the Empirical Formula ??

First note down the mass of rach element seperately.then divide it by Mr tht u find in periodic table.
There are chances tht the value is in decimal like 0.25:0.5
In this divide both of thm by least no. that is 0.25.u should not hv answer of this ratio in decimal so balance it accordingly.
Hope this helps

 

[Ahmed Nasser]

Thank u

 

[Ahmed Nasser]

can some one get for me june 2012 with mar schemes plus GT , thank u

 

[sparsha.mehta]

can some one get for me june 2012 with mar schemes plus GT , thank u

Which subject???

 

[Ahmed Nasser]

Chemistry :d

 

[sparsha.mehta]

Chemistry :d

http://www.mediafire.com/?mm7sbuurfkuuu#myfiles

 

[diamondsky]

Chemistry :d

http://olevel.sourceforge.net/papers/0620/