• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Physics: Post your doubts here!

Messages
1,229
Reaction score
740
Points
123
Somebody please help me out with this!!

Q: The pressure p and Volume V for a given mass of gas may be given by (p+a/v2) (V-b) = c.
Find the units of a, b and c.
 
Messages
8,477
Reaction score
34,837
Points
698
Somebody please help me out with this!!

Q: The pressure p and Volume V for a given mass of gas may be given by (p+a/v2) (V-b) = c.
Find the units of a, b and c.
You can't add a pressure to a temperature, it does not make sense. So the a/v2 must have units of pressure if it is to be added to p. Similarly b must have units of volume.
Therefore, b has units= m^3
a/v^2 must have unit the same as pressure so,
N/m^2 = a/(m^3)^2
a =Nm^6/m2
a =Nm^4
c = N/m^2 x m^3 = Nm
 
Messages
1,229
Reaction score
740
Points
123
You can't add a pressure to a temperature, it does not make sense. So the a/v2 must have units of pressure if it is to be added to p. Similarly b must have units of volume.
Therefore, b has units= m^3
a/v^2 must have unit the same as pressure so,
N/m^2 = a/(m^3)^2
a =Nm^6/m2
a =Nm^4
c = N/m^2 x m^3 = Nm
Thanks a lot.
May Allah bless you.
 
Messages
17
Reaction score
24
Points
13
Ans C. All other values are (integral) multiple of it. A and B are too small - no info about them from values given

THere was once are question like in multiple choice - one of the recent years. I don't remember which one though.
No its not C but B i have check it in the answer sheet.
 
Messages
174
Reaction score
371
Points
73
if you don't get an A* after studying these notes and practicing all these past exam questions (you are even provided with their solutions there), then REALLY i don't know what to do to obtain an A*.
I need notes apart from textbook and past papers doesn't help to score A* if it does then all the candidates SHOULD have had score A*.
 
Messages
17
Reaction score
24
Points
13
SORRY I made an error. Answer is indeed B. FOR the same reason I told you in my earlier post - due to the integral multiple. From ans C, we do not always obtain integral multiples. But with B, we can. A is wrong because if we divide ans B by integers, we would have to say that all of them are correct.

SORRY again.
hi can you plz post the answer in details and explaining the calculations you have done coz i am a bit confusing wiz the answer in the june 2012 paper. And thnks 4 the help;)
 
Top