Ask any difficulties about Engineering Mechanics, TOM, SOM, DOM & Vibrations here.. Let help others & get helped from others also. What do you think?
how r u preparing for mechanics!!???…which book!!??…is this the first time u r writing gate??…
This is my second attempt.
Anyway I am not actually bothering too much about “Mechanics” bz I know if I prepare for SOM, TOM, Vibration & DOME well then the “Mechanics-Problems” will be automatically prepared!
Remaining theory part concepts can be prepared from any standard book.
Also you will see there are hardly 1 or 2 questions on the Mechanics Section!!!!
There are two objects of mass ‘m’ connected over a frictionless pulley and are moving with velocity ‘v’.Inertia of pulley and friction is neglected.It is desired that the arrangement shd hv a max stopping time of ‘t’ from peak speed of ‘v’.What shd b the minimum power of the motor?(GATE 05 Mechanics question)
@chetan….u r right…we dont have to give too much stress on mechanics..since problems asked in mechanics arent very difficult(most of the times)!!!
and hey guys..have u joined any test series or coaching???…how ur analyzing ur performance from time to time??
@Ganesh, Frankly speaking I could not able to imagine the problem right!!! More explanation is needed 🙁
whether they give any figure along with the question?
You said this question is from GATE 05; please also state the stream (production, mech, civil) so that I can search this question there!!!
@Ritesh, Exactly, thats what I wants to say, concentrate more on our core subjects 🙂
Ritesh I haven’t joined any test series. Did you know any good organization??
@chetan,sorry for not describing it right.Basically its best explained with the help of figure…Its from mechanics section of gate ’05(mech).Its like an elevator and counterbalance system.The two weights are freely suspended over a pulley by means of an inextensible string.One mass is moving up with velocity ‘v’ so naturally the other is going down with ‘v’.Sorry for replying late.
@chetan..i joined targate test series…its very good!!!…but already six tests over…i doubt whether u can join now..!!!…how r u testing ur performance??…i attempted gate 2004 paper yesterday just like normal gate exam…scored only 55.25 out of 150…u can also do something like that..:)
@Ganesh, I got the question paper of GATE 2005 & read that question. Still I took much time to understand the question right. May be because of I am not aware of how exactly the elevator works. I always wondered that why that counterweight(CW) is there when we have electric motor in place. Then I googled it finally understands the use of CW is to save the energy.
Now coming back to the question;
Here, we can see the energy in the cage is in the form of K.E. which equals to, 0.5*m*v*v
Also K.E. in counterweight(CW) is, 0.5*m*v*v
Even the cage & CW are moving in opposite direction, they are pulling the chain in same direction (clockwise).
So combining the two K.E.
(0.5*m*v*v) + (0.5*m*v*v) = m*v*v
Now the motor should have minimum energy which could be able to oppose this combined energy. In other words, the motor should do “WORK” to oppose the K.E. which is equals to, m*v*v.
So, minimum work the motor must generate = m*v*v
Now as we know, Power = Work done / time
we can say,
Minimum power the motor must have = (m*v*v)/t
check out the answer.
@Ritesh, One of my friend also joined Targate test series. I think it is good organization; keep it up. If you find any interesting questions then you can post here on InI.
I am also going to solve previous years papers in January. Right now I am studying. Still lots of study is left. But I must practice some papers. I wish I can start practicing as early as possible. 🙂
@chetan,i dont have the keys but i think your logic is correct.Thank you…….
For those who don’t know the question asked by Ganesh, Here it is:-
Please right click the link and click on “open in new tab”
my kind advice friends . gateforum targate test series is good but pls do not go for clasroom coaching . It is a waste of time and money . I am an ex gateforum student . this year i have taken coaching from DYNAMIC INSTITUTE , its solely for mech engg. and prof ramasubramaniam has given great results and his teachings are the best . if u attend his classes regularly and make use of his notes I would certainly assure you will Clear the exam with ease . you will get used to the gate pattern so well and you would do well in the interviews too .
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