# Physics, Chemistry and Biology: Post your doubts here!

#### Hamkha

Hi again Anon.....Ive been seein u around lately....
Now cn u also solve this problem for me pls????? ^-^
A uniform metre ruleof weight 0.9N is suspended horizontally by 2 vertical loops of thread A and B placed at 20cm and 30cm from its ends respectively. Find the distances from the centre of the rule at which a 2N weight must be suspended:
i) to make loop A become slack
ii) to make loop B become slack
Hi every one here. Please any one can help for this question?

#### Ilyas Raza Khan

Assalam-o-Alaikum.
Post your Physics, Chemistry and Biology doubts in here and members, along with me will try their best to help you out.
I need book chemistry calculation of ja hunt and asykes

#### gauravkgoyal17

Need these workbooks urgently.

#### Waania

Assalam-o-Alaikum.
Post your Physics, Chemistry and Biology doubts in here and members, along with me will try their best to help you out.
Can you explain how cardiograms work? Im a lil confused

#### Shaykh Subhan Gul

Can you explain how cardiograms work? Im a lil confused
Dear, I'm a Biology Teacher - teaching OL/IGCSE/AS/A2 from a long time.

WhatsApp me
00966571442094

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#### Waania

A plastic cube, of density p , is compressed so that each of its sides becomes one-half of its original length. What is the new density of the material of the cube? A 0.125p B 0.50p C 2.0p D 8.0p

#### xandarbander

Hey!!! Does anyone know what came in physics 5054 paper 22?

#### xandarbander

A plastic cube, of density p , is compressed so that each of its sides becomes one-half of its original length. What is the new density of the material of the cube? A 0.125p B 0.50p C 2.0p D 8.0p
Take a cube of 1/2 and the answer would be 1/8. So if the volume reduce to 1/8 then the density increases to 8. (Density= mass/volume)

#### aleeeza

Need these Coursebooks/Textbooks in PDF.
Physics for Cambridge IGCSE Coursebook 4th Edition (Textbook) By David Sang
Chemistry
for Cambridge IGCSE Coursebook 5th Edition (Textbook) By Richard Hardwood & Ian Lodge
Biology
for Cambridge IGCSE Coursebook 4th Edition (Textbook) By Mary Jones & Geoff Jones

#### Cedrick

Need these IGCSE for Campridge O'Level textbooks pdf
Chemistry
Biology

#### Cedrick

in crystallisation you heat the solution then cool it down quickly ,this makes the molecules of the salt bind some water molecules around them forming crystals
in evaporation ,u remove all the water , so the salt is like a powder .also if you heated a crystallised salt ,you'll remove the water of crystallisation and it turns to powder.
yes, both are ways of extracting substances from solutions ,but evaporation can be done when the substance don't dissolve in the solution ,but for crystallisation to occur the substance has to dissolve in the solvent
Hallo can you please kindly send me this book in pdf form

### Cambridge IGCSE & O Level Biology: Exam Success​

#### Bhai_Shaib

Is there anyone who has Chemistry o level Topical Book? mean Questions with solutions)

#### idurufrancis

Good evening everyone
Please need help in getting any good textbook for IB chemistry @ secondary school and Higher level

#### MG guy

can someone explain these things, i am not understandng, frustrated as heck

#### Ongani

Assalam-o-Alaikum.
Post your Physics, Chemistry and Biology doubts in here and members, along with me will try their best to help you out.

#### shahanazasif

Website for O/A Level notes.

#### Safia1974

Assalam-o-Alaikum.
Post your Physics, Chemistry and Biology doubts in here and members, along with me will try their best to help you out.
Hi, does any body have solution manual of Physics matters please?

#### tangeni abel

hi does any body have old question papers for grade 10 - 11