Here's the question you clicked on:
mayankdevnani
State that WORK is DONE or NOT..... A Wind-Mill is lifting water from a well. and also justify your answer..
am confusing.....plz help me
for windmill work is not done and for water work is done!
no @VV-EFF question is one!!
work is done then! because windmill is applying force to pull up the water and the water itself displaces! now it depends on the angle between the force applied by the mill and the direction of water!
yaa.. i know but my teacher says the work done is zero..
she would be considering cosQ =0, then she's right
can you help me @ganeshie8 and @gerryliyana
what is this? i can't understand
workdone=FxDxcos(Q) where Q is the angle between the force F and displacement D.
the work done is zero., because windmills always return to the original point
how can we know that angle is of cosQ
yeah thats the point @gerryliyana ! he is considering water anf mill, both as a system!
and in case of water ! water is displaced by force!
work is done then! because windmill is applying force to pull up the water and the water itself displaces! now it depends on the angle between the force applied by the mill and the direction of water! @gerryliyana in this case!!
so in that case...
nice What! @gerryliyana ! gve him the answer man! lol....
so finally whats the conclusion of this answer.
@Aperogalics have a look!!
the conclusion is that if u are considering the both as a system then the work is done ; iff Q is not equals to 1.5707. and if the system is only the mill then the work is said to be not done!!
but the answer is to be written is one
in my solution book answer is work is done and the reason is that windmill pulls the water against the gravity...
@mayankdevnani there are two thing work done by the system and work done on the system here if the system is windmill then work done by the system is zero as there is no net dispacement while work done by the system is +ve as he make the water to be displaced........:)
obviously !!!!! @mayankdevnani if its against the gravity the according to the equation F=ma , water has mass and the acceleration is .9.8 mLsecsquare! then the force definitely exists ! and so the workdone!
so what's the answer??
now dude stop confusing your self! the answer is that the work is certainly done by the system!
m really confused @Aperogalics and @VV-EFF what is the concluded answer and answer should be one means both work done or not
so i am correct and my teacher is wrong!!!
work is done by the system! its certain!
sure...are you sure about this!!
let @Aperogalics be write and then think,. he has creative mind...let @Aperogalics be answer
@mayankdevnani @VV-EFF is very clever he is still saying work is done by the system if ur mam is talking about work done on the system then she is correct and if not then you are correct.........:)
no my mam says that the work be zero and i say that work is not zero @Aperogalics
lol.. what an answer @Aperogalics
@mayankdevnani yes ur mam says work is zero but is it by the system or on the system??????????? do you know about which she was talking about??????????????
no.. my friend george said that mam says the work done is zero
my senior friend also says that _____ "lifting water" is the work that is done. When anything is lifted - it is moved (displaced) upward against the force of gravity. The force that lifts the object (water) must be greater that that of gravity or the object won't displace upward. The Net force that acts upward to lift (object, water, etc) multiplied by the vertical lift height is defined to be the work done in this process.
secondly, there are not more than one work done... right..
lastly , what's the concluded answer suppose you are in examination hall and you have a pen and this question ...how would you solve it? @Aperogalics and @VV-EFF
i would say that u plz read the conversation above! and conclude the answer urslf!
@mayankdevnani answer my question and you will get the answer by yourself:)
a basic question in every book suppose a man lifts a box to his head and walk 40kms . IS THE WORK DONE BY THE PERSON?
no work done is zero
because force acts in perpendicular direction\[90^{0}\] and displacement is at right angle
right @Aperogalics
is the work is done against gravity?????
|dw:1352199535611:dw|
why thats have no answer
yes that's the thing force is applied against gravity and displacement is zero here|dw:1352199714164:dw| there displacement is in perpendicular direction and here no displacement
always for you help here i asked 2 different question bith r work but done by different systems.....k:) so if the question is of IIT then it will mention the system otherwise my first post is the answer:)
I will say a small thing that "pulley" is the main thing here... |dw:1352284103729:dw|
nice @SheldonEinstein
THanks @gerryliyana :)
@SheldonEinstein so that the work done is zeroo..you would say that
I had said that and yes Work done is ZERO! (if we are talking about a diff. kind of system)