[Zhy]

I think materials is a bit easier. Although mechanics does get you out of trouble in AS Physics (M3 strings and springs is really helpful). M4 is kind of helpful for the relative motion but the relative motion questions in AS Physics are very easy.

[99llewellyn99]

where can i get the specs

[Zhy]

specsavers mate

[Salmonidae]

(Original post by 99llewellyn99)
where can i get the specs

Here http://www.edexcel.com/migrationdocu...4%20260510.pdf

[99llewellyn99]

could you post a link or sumthing coz i cant seem to find it

[99llewellyn99]

(Original post by Salmonidae)
Here http://www.edexcel.com/migrationdocu...4%20260510.pdf

thanks

[The_New_Guy]

Could anyone give precise meaning of the following terms?
1.Elastic limit.
2.Yield point.
3.Plastic deformation.
4.Tough.
5.Hard.
Is elastic limit beyond the proportionality limit?
What is the difference between ductile and malleable?

Please help me guys.Your help is appreciated.

[youlostme]

(Original post by The_New_Guy)
Could anyone give precise meaning of the following terms?
1.Elastic limit.
2.Yield point.
3.Plastic deformation.
4.Tough.
5.Hard.
Is elastic limit beyond the proportionality limit?
What is the difference between ductile and malleable?

Please help me guys.Your help is appreciated.

elastic limit: the point on a stress-strain graph beyond which the material will not return to it's original size whe the stress is removed

yeild point: the point beyond which the material will start behaving plastically and will show a large increase in strain for a small increase in stress

plastic deformation: when the material starts behaving plastically, it is permenantly deformed and will not return to it's original size/length when stess is removed

tough: tough materials can withstand large imapct forces without breaking and require large stress to produce a small plastic deformation

hard: hard materials resist plastic deformation by clenting/scratching (eg: diamond resists deformation by denting another surface)
elastic limit is beyond proportionality

malleable solids can be reshaped easily without fracturing(can be made into sheets)

ductile solids can be drawn into wires

note that they both react the same way to stress(ie if you draw a stress-strain graph for both of them, they will be identical)

[Salmonidae]

(Original post by The_New_Guy)
Could anyone give precise meaning of the following terms?
1.Elastic limit.
2.Yield point.
3.Plastic deformation.
4.Tough.
5.Hard.
Is elastic limit beyond the proportionality limit?
What is the difference between ductile and malleable?

Please help me guys.Your help is appreciated.

Ok:
Elastic Limit : this is the point where a material no longer behaves elastically (I.e won't revert back to original shape) and plastic deformation begins.

Plastic deformation : Plastic deformation is where something is deformed and won't just spring back, for example if you bend a piece of metal.

Yield point : this is where a material starts to stretch without any extra load (think of a force extension graph flatlining)

Tough: can absorb a lot of energy without breaking

Hard : difficult to scratch/indent or cut - diamond is hardest material.

Yes elastic limit is beyond limit of proportionality, just after the line starts to curve generally.

Malleable means it can be plastically deformed by compression (think hitting with a hammer) and ductile means it can be pulled and stretched out (into wires).

Hope that helps S

edit: someone beat me to it! Well now you have 2 interpretations

[cisne]

(Original post by The_New_Guy)
Could anyone give precise meaning of the following terms?
1.Elastic limit.
2.Yield point.
3.Plastic deformation.
4.Tough.
5.Hard.
Is elastic limit beyond the proportionality limit?
What is the difference between ductile and malleable?

Please help me guys.Your help is appreciated.

PROPORTIONAL LIMIT: Point up to which the material obeys Hooke’s law
ELASTIC LIMIT: A maximum force at which the material regains original shape when the force is removed
YIELD POINT: Point at which material’s behavior changes from elastic to plastic
BREAKING POINT: Point at which material breaks (this point always occurs beyond elastic limit)
TENSILE STRENGHT: The tensile stress at which the material breaks
DUCTILE: Materials which show plastic deformation
BRITTLE: Materials which break or crack with little deformation
TOUGH: Materials able to withstand impact forces without breaking and require a large force to produce a small plastic deformation (tough materials are not brittle)
HARD: Materials which resist plastic deformation, usually by denting
MALLEABLE: Materials which shows large plastic deformation before cracking or cracking (not brittle and not necessarily tough...It is a similar property to ductility, as a malleable material can be reshaped easily without fracturing)

[Zhy]

Where do you guys get the definitions from? I made a list just from going through every mark scheme I could find, but is there some kind of official glossary?

[99llewellyn99]

1. elastic limit is the point to which a material can be stretched until if it is stretched any further it remains plastically deformed
2. yield point is the point after which the material begins to show a large increase in strain for a small increase in stress.
3. plastic deformation is when an object is stretched beyond its elastic limit and doesn't return to its original shape when released
4.tough objects are the opposite of brittle objects they are able to withstand impact forces without breaking and require a large force to produce a small plastic deformation.
5. hard materials don't get scratched, cut or indented easily they resist plastic deformation.

elastic limit is after limit of proportionality if u have the edexcel AS physics textbook look it up on page 68

a ductile material shows large plastic deformation and can be drawn out into thin wires. gold and copper are ductile.
malleable objects are those that can be hammered into shape or flattened out gold and copper are also malleable however iron is the most common example

[99llewellyn99]

(Original post by Zhy)
Where do you guys get the definitions from? I made a list just from going through every mark scheme I could find, but is there some kind of official glossary?

check out the TEXTBOOK or if you have the active book click on words you want to know the meaning of or simply google it

[Zhy]

Can someone draw out the stress-strain graphs for the different types of materials in comparison to each other? (e.g. tough, hard, brittle, malleable, ductile, plastic, elastic, strong, stiff, durable)

[youlostme]

(Original post by 99llewellyn99)
check out the TEXTBOOK or if you have the active book click on words you want to know the meaning of or simply google it

yeah just check the text book all graphs you need to know are in there

[The_New_Guy]

you guys are amazing!
Thanks for the help.

[cisne]

(Original post by Zhy)
Where do you guys get the definitions from? I made a list just from going through every mark scheme I could find, but is there some kind of official glossary?

Hei...Do you have the old spec mark schemes???

[ShmangoBaby]

What parts of the unit do you guys find hard?
I just hate all the resultant force,tension stuff., Eventhough its pretty easy they can be quiet tricky and stuff..

[ShmangoBaby]

And also, does anyone have any good revision notes?
Please post if you have any notes/links. Thanks!!

[Top Hats]

If I open the paper and there is a bloody question about a bloody ping pong ball I will hunt down the Edexcel examination officer and play ping pong with his balls.

Just saying.