@CalvinKhor you don't know he was wayward. That day he insisted I called him when I arrive his place before 8: 15 even though I said I can't call because my phone card has been overdue. Then when I arrived his place, I asked the guard to contact him using various ways, calling him by both kinds of phones, pressing his home bell, but he didn't respond to all.
then the guard asked me to directly go to his room to find him.
then when I went there, I knocked his door for long, but he didn't open his ddor.
then finally I determined to open his door on my own.
when I opened, I found he was not in.
and that's when 8:15 just passed.
obviously he was fooling me around.
so I determined to take my luggage on my own.
when I took my luggage and was going to leave, he came back.
@CalvinKhor Can you please suggest me a book which teaches the kinemarics of rigid bodies, things like Center of mass, acceleration of Center of mass and rotational kinemarics (it should be introductory book, not advanced)?
@CalvinKhor I just turned down all his invitations to hang out with him or dine with him or go to his school with him when he wants to look for his MSc supervisor and turned down his harassment by asking to do chores or asking him not to disturb my serious work.
@AmandaMacaurenni Yes, you definitely need to know basic things like change of coordinates and invertibility of linear maps to understand what a manifold is; diff equations are used to define geodesics but i think you can 'pretend' you understand that more easily
@CalvinKhor when i was studying SHM i came across $ F = kx $ which is essentially the diff eq $ y'' = ky $, right? now this eq, to my observation, can have two solutions (and in reality, maybe more). one of them is of the form i saw on those chapters, $ y = c_1 cos(kx + c_2) $.
the other is, $ y = c_1 e^{ \sqrt{k} x + c_2} $, which i end up finding on the internet after a failed attempt to derive eqs for SHM by myself. so, my question is, i have satisfied the diff eq. so can i use the second eq as an eq for SHM too? if not, why?
@AmandaMacaurenni you should define if k is positive or not. In shm we F=-Kx because it is restoring force. And by this you will get sin or cos function only
I pretend to not know a thing at first then when I know something that's when I am the most dangerous so it's good for me to shut my mouth up for a moment in differential equation lol
@CalvinKhor Can you please suggest me a book which teaches the kinemarics of rigid bodies, things like Center of mass, acceleration of Center of mass and rotational kinemarics (it should be introductory book, not advanced)?
@satan29 @NoseBleed Resnick or Sears and Zancky doesn’t have topics like : rolling without slipping, frictional torque. These topics are asked in Irodov’s problem book
An elevator is connected to its main cabin at the top of the building, suddenly it's wire (by which it was connected to the main cabin) breaks and starts hanging, the man inside the elevator catches the string and is pulling the strings so as to keep the whole system in equilibrium. What will be the weight of the man?
Given: mass of man = 100 kg, mass of elevator = 40 kg.
I too don't know, but when I asked for clarification the questioner said "the elevator was on a pulley system, so when the cable breaks, the part which was connected to the elevator started hanging down and then man catches it"
Look at the diagram. The rope is attached in two places, one to the elevator and one to the man, and at both places it exerts an upwards force $T$. So the total upwards force is $2T$.
@AmandaMacaurenni what @SMSheikh said is exactly correct. In SHM, the spring pulls back on the mass which causes the block to accelerate in the opposite direction. So your $\sqrt k$ is actually $i\sqrt{|k|}$ and the two formulations are equal because $e^{ix} = \cos x + i\sin x$
Check the room description @CaptainBohemian, it’s some javascript you can bookmark. When you enter a chat room you can click your bookmark and latex will render like math.se
because I read men and women react to depression differently - while men react by irritability to depression, women react to depression by withdrawal from socialization.
First it started with locking myself into room, then lack of appetite... (I actually lived for 2 week with a single time meal, sometimes, no meal), sudden trauma.... (For example, I'd wake up several times during sleep for no reason with that triggering my taruma, sweating, heavy breathing.... then walk for 20 min to get normal then back to sleep... Usually happened for 3 times during night sleep)
Forgetting things like age (sometimes).... own birthday...
