Qualification > Sciences

P.H.Y.S.I.C.S P2 D.O.U.B.T.S CIE

<< < (20/39) > >>

The SMA:

--- Quote from: halosh92 on June 07, 2010, 01:51:15 pm ---Q4a
brittle: when the ultimate tensile stress occurs at the elastic limit ( thats when it breaks)
ductile: it can stretch after the elastic limit ( it becomes plastically deformed) then it some point it breaks
plastic: they usually have a low stress value and a large area under the graph , in the begiinng they are ductile but as stress increases they become plastically deformed

Q4c: stress= force/area
first find the minimum area of the tube from the graph , the highest stress is 9.5 * 10^8
area= (1.9 × 103) / (9.5 × 108)
= 2 * 10^-6
maximum area is given in the question
so subtract the minimum area from the maximum

--- End quote ---

Thanks! I got it now ^^

The SMA:

--- Quote from: AN10 on June 07, 2010, 03:39:23 pm ---i dnt get da last step...y do we subtract the areas ???

--- End quote ---

we need to minus bcoz we want to find the max area which is (3.2*10^-6)-(2.0*10^-6). not the min area we solved earlier.

sweetie:

--- Quote from: nid404 on June 06, 2010, 05:14:45 pm ---
phase difference=( 2pi/ lamda)  X path difference

phase difference = pi [ for destructive interference]
lambda(wavelength) = 2pi/ pi  X path difference.
path difference is S2M - S1M 
find S2M using Pythagoras = root of 802 + 1002
                                                   =128
path difference= 128-100=28
wavelength= 2pi/pi X 28
               =56cm                 
At f= 1KHz wavelength= 0.33m/ 33cm
At f=4kHz   wavelength= 0..0825/8.25cm
wavelength changes from 33cm to 8.25cm
for minima...phase difference should be either one of them pi, 3pi,5pi,7pi [sub them in the eqn]
minima is observed when lambda= 56cm, 18.7cm, 11.2cm, 8cm
which are the 2 values between 33 and 8.25?? 18.7 and 11.2...so only 2 minimas


--- End quote ---

Thank You nid... +rep

but is  "phase diff.=2pi/lambda *path diff "  a given formula or u derived it on ur own???

sweetie:
cn u xplain Q 7bii

zxcvbnm:
november 05, question 8, last part...can someone uplaod the curve drawn? please asap

Navigation

[0] Message Index

[#] Next page

[*] Previous page