Physics p22

[Hateexams93]

can we talk about it now ?

 

[hassam]

yea ,,,,so how did it go

 

[Bibiology]

I believe it was easy bt time wasn't enough especially for that young modulus ques I kept on repeating stuff..
Gt will be low around 40..

 

[hassam]

k ...did samebody wrote on the need to take a lot of readings of Force and extension...calculationg stress and strain...drawing line of best fit..stress against strain graph...determining its gradient.......this is i guess the best way to determine young modulus.....cos only one set of reading will giv a large error

 

[hassam]

this is for last part of that queestion....and taking measurements....i wrote that pulley wla experiment........mentioned in CHRIS MEE book

 

[workinghard]

i did that all the stuff u tlkd bout
but mentioned 2 tak several readings in 2nd part...

n time wx really 2 short!!!
i think i messed up a few things :'(

 

[Mueez]

yess,.... i wrote about repeating exp with different values of weight nd different diameter of wire

 

[Mueez]

what did u write in
why only one laser is used instead of 2

 

[thunderingthunder]

k ...did samebody wrote on the need to take a lot of readings of Force and extension...calculationg stress and strain...drawing line of best fit..stress against strain graph...determining its gradient.......this is i guess the best way to determine young modulus.....cos only one set of reading will giv a large error

about that young modulus i also wrote something lyk this!!

 

[hassam]

y will u want to change diameter since u cn get a range of stress values by using different weights only....and using different diameter will not be feasible i guess

 

[hassam]

and what abt the sketch graph.....guyx...i did lyke initailly it was overlapping and....its final velocity reached was less....than for drwan case....bt i guess it should have been all the way below the original graph so guess m loosing 1 mark frm here

 

[jason3991]

and what abt the sketch graph.....guyx...i did lyke initailly it was overlapping and....its final velocity reached was less....than for drwan case....bt i guess it should have been all the way below the original graph so guess m loosing 1 mark frm here

Um..shouldnt it be higher,because it has less surface area...so it will fall faster...and also reach terminal velocity at a later time?

 

[hassam]

no...man see...u decreased the radius....so u decreased the volume...so mass decreased so its lighter....lighter means it ll reach terminal velocity earlier...cn u remind me of that F equation

 

[hassam]

bt its initial acceleration will be higher....now i got it...see a=6piRv/ d*4/3pi r^3....so u decrease radius u decreasing the denominator so.....u increasing a .......i think this shud be anser though i drew it initially higher bt dont knw wat asked me to erase that and cause it overlap the drawn graph

 

[jason3991]

so its higher right??? and reaches terminal velocity at a later time

 

[workinghard]

i also made it higher
oh plx let it b rite
i already made so many blunderx

 

[hassam]

well cn u tell me how u calculated acceleration......

 

[workinghard]

@ hassam...i can but i wont
like i tld u i messed up everythin
n i hate it wen i lose marx n make more blunders in comn pprx...
so plx dont evn tell da ans,,,,
4m da sound of u u got ur ppr rite n it kills 2 hv done such a messed up ppr...
n i d appreciate it if nobody else tells da ans...

 

[hassam]

bt u only tell me method and i also dont rememba anser...mayb i too messed it up

 

[boy2011]

i calculated aceleratn first by calculatng volume by 4/3pi r^3 and then frm density frmula i found out its mass and then put in da formula f=ma