Topical Pastpapers Physics

[libra94]

okk for this question what i did was, i made eqal sizes of bubbles along the diameter of the cylinder. so there were 5 bubble in total along the diameter.
then i said that 5 bubbles=5 times more diameter than 1 bubble = 10 times more radius than 1 bubble
so 3.2*10^-6= 3.142 (pi) 10r^2
then u can find radius of one bubble
then use this r to fing the cross sectional area of the bubble

 

[rz123]

once again u r dre to help i like dat but miss dis diagram is not scale! so how can u draw things nd get result , well i think we need to use some formula. Think Think Think! i am stuck at this question .

 

[libra94]

i think there's somthing to do with stress cuz we hav force and the area...so something to do with stress which is force/area

bt my way also gave the same answer :shock:

 

[rz123]

this stress question is putting a lot of stress on me. marking scheme says minimum c.s area is calculated by taking the stress from the b part and the force from the cylinder subtracted from the c part cylinder c.s area gives the bulbala area. now how on this Earth is this possible :|...choro paran goli maaro is question ko

 

[libra94]

this stress question is putting a lot of stress on me. marking scheme says minimum c.s area is calculated by taking the stress from the b part and the force from the cylinder subtracted from the c part cylinder c.s area gives the bulbala area. now how on this Earth is this possible :|...choro paran goli maaro is question ko

lol...yeah i didnt get the marking shceme
waisay bhi i gt the same answer as the ms :/
anyways i'll work out to find how we get the area of bulbula lol

 

[libra94]

oh i think i got it
the minimum area is the area of the cylinder during the breaking point...cuz when its at the breaking point the diameter decreases so therefore the cross sectional area.
so to get the min area....stress=force/area
area=force/stress at breaking point(frm the graph)
(1.9*10^3)/(9.8*10^8)= 1.9*10^-6

then to get the area of the BULBULA we subtract mim area by max area
so,3.2*10^-6 minus 1.9*10^-6
======> 1.2*10^-6 m^2

 

[rz123]

ahan this makes some sense thanks, me toh kab ka is question ko bhool gya hun and dat pani ka bulbala also...

 

[libra94]

ahan this makes some sense thanks, me toh kab ka is question ko bhool gya hun and dat pani ka bulbala also...

bhoolna nhi chahye naaa. what if this type of question comes in the exam? what will u do then?

 

[rz123]

i will call u then lol open xtremepapers forums via mobile . well yeah should take these type of questions as a challenge. :|

 

[libra94]

i will call u then lol open xtremepapers forums via mobile . well yeah should take these type of questions as a challenge. :|

yeah sure why not?
yeah we must take these type of questions as a challege whether we can do it or not.

 

[rz123]

aww dats so kind of you but i hope aesi noobat na hi aey, want to be fully prepared bf4 exams so that i can tackle any type of question.

 

[libra94]

aww dats so kind of you but i hope aesi noobat na hi aey, want to be fully prepared bf4 exams so that i can tackle any type of question.

yeah, thats like a good student

 

[rz123]

haha well u seem to have good command over the subject or maybe you are studying with the right approach. BOL

 

[princesszahra]

wooowww! i wish u posted this in my time!

 

[libra94]

haha well u seem to have good command over the subject or maybe you are studying with the right approach. BOL

hmm, so r u

 

[rz123]

then what would have happened ? and what r u studying currently?

 

[libra94]

then what would have happened ? and what r u studying currently?

m doing AS..phys,chem and bio this May InshaAllah.

 

[rz123]

InshaAllah nice AS is good , confidence booster and takes half burden away if perform well! but i am not giving as my performance was mediocre in mid term school exams.

 

[libra94]

InshaAllah nice AS is good , confidence booster and takes half burden away if perform well! but i am not giving as my performance was mediocre in mid term school exams.

yep hmm, its okay u can do better nxt time

 

[rz123]

hope so, have to utilize fully vacations. actually i lack intensive past ppr practice which is key i think. :|