Question

ok they had given pendulum done 100 oscillation its amplitude reduced to 1/3 of initial value. what will be its amplitude if it completes 200 oscillation

Answer 1

100 oscillations in what time period?

Answer 2

dont solve just tell me ur vies dat how will u suppose to handle this ques plz plz but dont solve

Answer 3

*view
they didnt give time period so we can assume it constant??

Answer 4

I still don't understand the question. Is it this:

"In a given time period a pendulum completes 100 oscillations.

"Then the pendulum has its amplitude decreased by 1/3 and it completes in the same time period 200 oscillations."

If so, what's the question here.

Answer 5

no they didnt said anything abu time period even i m asking can we assume it constant

Answer 6

What is true about a pendulum is that if you increase the angle of maximum oscillation more than about 10 degrees, the period of the pendulum increases. The reason for that is in calculating the standard period of pendulum, we use a small angle approximation
\[ \sin\theta \approx \theta \]
which only holds for small angles \( \theta \).

The wikipedia article has good animation of what happens when \( \theta \) gets large and there you can see the period increases.

http://en.wikipedia.org/wiki/Pendulum#Period_of_oscillation

This would explain the effect described in this set up.

Answer 7

but james my ques how i m gonna solve it ? any hint or idea even i m trying hit and try but u can tell ur one too that it might like dis?

Answer 8

u guys have any idea?

Answer 9

it is saying that when pendulum completes its 100 oscilation its amplitude reduced to 1/3 of its inital means 2/3 is remain of apmlitude i guess and then they are asking if it completes 200 oscilation than what will be the value of amplitude

Answer 10

i think amplitude decrease

Answer 11

i need a value too.. :P

Answer 12

Oh, I see. Precisely what is the amplitude, in angular terms. Use the first couple of terms of this expansion:

Answer 13

god.. u r kidding james by showin me dat short formula rit ...

Answer 14

i thinks in that i m not getting they are squaring or wat?? inside the bracket?

Answer 15

hello. i am back.

Answer 16

with 100 oscillation amp 1/3 decrease so with 200 oscillation again decrease 1/3 im not sure

Answer 17

You know that T decreases by a factor of a 1/2. Use that formula to find what value of theta_0 will make that happen.

Answer 18

may i help here?
May i could do something?

Answer 19

yea solve diss ques

Answer 20

ok wait. let me analyze.

Answer 21

i wasted 15mins in this ques yar

Answer 22

plz quick

Answer 23

james formula is correct?

Answer 24

yea but unable to aplly
a i nvr heard abu dat one

Answer 25

james formula abu period of oscillation,not amplitude

Answer 26

now what i understand. BUT THIS QUESTION LOOKS INCOMPLETE. look here

first calculate time period using
T=1/f
T=1/100
T=0.01sec

Answer 27

guys i need the ans 1/9 nw think ow can we get

Answer 28

f=? y u put ocilation??

Answer 29

idont understand u'r sentence?

Answer 30

i mean the ans of this ques is 1/9 now just hit and try to get this ans

Answer 31

how can you got it?

Answer 32

no i dont got dat i had ans key :) and my ans is not matching dats why i ask for help..

Answer 33

now use the displacement equation,
y=Asinwt
where w is the frequency.

y=(1/3) sin(100*0.01)
y=(1/3)(0.0174)
y=0.005m

now use this displacement as,
0.005=Asin(200*0.01)
0.005=A(0.0348)
A=0.143

:( is this wrong?

Answer 34

there is no other way to do it. so it tried my best. and result is before you. :((

Answer 35

i want to cry.. :"(
)............
)............................ god if this kind of ques coming on exam i m gonna dead

Answer 36

what is exact answer?

Answer 37

i am sure it is right.

Answer 38

1/9 i meantion it too

Answer 39

1/9 is equals to 0.1. so it is right. may be.

Answer 40

yes u r rit u got it congo.........

Answer 41

congo?

Answer 42

but in ur equation asinwt
here t is time not time period

Answer 43

Heena. Let's try this one last time. Write out the complete question in your best English.

Answer 44

lolz.. ok

Answer 45

ithink shayan answer is wrong.

Answer 46

when an osicllator completes 100 oscilation then its amplitude reduced to 1/3 of its initial value of amplitude.what will be its amplitude if an osicllator completes 200 oscilation

Answer 47

This question is still very ambiguous. It means either

* The time periods for the 100 and 200 oscillations are different and just a distraction. The amplitude is 3rd of what it is and that's the end of it.

* We're talking about a pendulum and the period of oscillation changes. In which case we need to use the formula I wrote above

* Something else.

Answer 48

i know.
when i said it is true. it may be wrong. i just tried. although i am an electronics engineer not a theoritical physicist.

Answer 49

guys had a idea leave it even i already wasted 30 mins in this ques better to leave this i ll ask my lecturer dont worry

Answer 50

yeah, good idea.

Answer 51

thnQ for being here for help ..
i always gave good ideas u knw gyan guru :P

Answer 52

why gave me medal i can't solve your ques

Answer 53

well i am going. good luck every one. take care.

Answer 54

hey medal is not for only those who solve the ques but its for those too who atleast tries to solve it ok

Answer 55

and i think u deserve as u given ur precious time to had a luk a my ques and tries it to solve as a help thnk you so much

Answer 56

this medal have not a value,i think
however thanks for your attention
sorry my english not well

Answer 57

np i apreciate everyones work they did for helping others dats the main moto to give medals atleast people help others for medals.. and dnt think u dont solve dis medal is for ur work out in this ques ok..