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Urgent A level Physics help! :(

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Reply 20
Avatar for Andy98
Andy98
20
Original post by hamza772000
Oh, sorry my bad, my brain's dead at this hour :tongue:

I know force in base units= kgms^-2


Exactly, so a Newton metre is just that multiplied by another unit of distance.

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Original post by hamza772000
Oh, sorry my bad, my brain's dead at this hour :tongue:

I know force in base units= kgms^-2




Tag in the guy with numbers he should know, he's doing a maths degree.
Number density will be measured in m^(-3), not kg/m^3.

It is defined as the number of electrons per unit volume.

A number has no units, volume has units of m^3 - hence 1/m^3 = m^(-3)
Original post by Andy98
Exactly, so a Newton metre is just that multiplied by another unit of distance.

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so kgms^-2*m?

Original post by Grimm Reaper
Tag in the guy with numbers he should know, he's doing a maths degree.
Dw, it's fine Grimm :smile:

Original post by kingaaran
Number density will be measured in m^(-3), not kg/m^3.

It is defined as the number of electrons per unit volume.

A number has no units, volume has units of m^3 - hence 1/m^3 = m^(-3)
So number density in base units= m^-3?
Original post by hamza772000


So number density in base units= m^-3?


Well yeah?
Reply 25
Avatar for Andy98
Andy98
20
Original post by hamza772000
so kgms^-2*m?

Dw, it's fine Grimm :smile:

So number density in base units= m^-3?


Yes, so simplifying that gives you....
Original post by kingaaran
Well yeah?
This says otherwise, no?

ads.png
Original post by Andy98
Yes, so simplifying that gives you....
kgm^2s^-2?
Reply 28
Avatar for Andy98
Andy98
20
Original post by hamza772000
This says otherwise, no?

ads.png


Those all relate to the mass, number density just relates to the number

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Original post by Andy98
Those all relate to the mass, number density just relates to the number

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Oh, sorry yeah, I failed to recognise the Kg i there :redface: so it's m^-3..
Reply 30
Avatar for Andy98
Andy98
20
Original post by hamza772000
kgm^2s^-2?


Correct

Original post by hamza772000
Oh, sorry yeah, I failed to recognise the Kg i there :redface: so it's m^-3..


It's OK dude, we all have our moments

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Original post by Andy98
Correct



It's OK dude, we all have our moments

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Ok, so one final time pls, 1 N m= kgm^2s^-2, 1nm= 1*10^-9? 1 mN= kgms^-2*10^-3? and 1 MN= kgms^-2*10^6, do these even make sense? :frown:

and m^-3

sorry for bothering you too much :redface:
Reply 32
Avatar for Andy98
Andy98
20
Original post by hamza772000
Ok, so one final time pls, 1 N m= 1 kgm^2s^-2, 1nm= 1*10^-9 m? 1 mN= 1 *10^-3kgms^-2? and 1 MN= 1*10^6kgms^-2, do these even make sense? :frown:

and m^-3

sorry for bothering you too much :redface:


I've rectified the answers in the quote

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Original post by Andy98
I've rectified the answers in the quote

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Oh, I get it, love you bro thank you sooo much <3 :h:
3) Nm is unit of torque derived by Force x distance, force is mass x acceleration so in base units Nm = kgm^2s^-2, nm is a nanometre, mN is a millinewton and MN is meganewton.
4) It is asking for number density so think of it as number of electrons per volume, since number of electrons has no units the base unit for it would just be m^-1.
Hope this helps.
Original post by JackMorgan32
3) Nm is unit of torque derived by Force x distance, force is mass x acceleration so in base units Nm = kgm^2s^-2, nm is a nanometre, mN is a millinewton and MN is meganewton.
4) It is asking for number density so think of it as number of electrons per volume, since number of electrons has no units the base unit for it would just be m^-1.
Hope this helps.
thanks, but it should be m^-3 as it says density, no?
Reply 36
Avatar for Andy98
Andy98
20
Original post by hamza772000
thanks, but it should be m^-3 as it says density, no?


Correct

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Reply 37
Avatar for Andy98
Andy98
20
Original post by JackMorgan32
3) Nm is unit of torque derived by Force x distance, force is mass x acceleration so in base units Nm = kgm^2s^-2, nm is a nanometre, mN is a millinewton and MN is meganewton.
4) It is asking for number density so think of it as number of electrons per volume, since number of electrons has no units the base unit for it would just be m^-1.
Hope this helps.


It's OK dude, it's done

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Original post by Andy98
:wink:
Reply 39
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Andy98
20
Original post by hamza772000
Oh, I get it, love you bro thank you sooo much <3 :h:


Yeah, something like that:tongue:

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