Recent content by apst

What direction is it north of the north pole? True, this question has no answer. It is very hard to digest, but maybe that British physicist was right. I don't know his name, but he said : "just as we cannot expect a chimpanzee to understand quantum mechanics, our universe might be populated...

I'm sorry. I can't even say oops. Before the big bang, however, did "things" exist? Particles? I know there is no specific answer yet, but surely, there must be assumptions... which I cannot find anywhere... That suggests that we chose to count time from the Big Bang... but the flow was always...

I found this on wikipedia: Indeed, such a treatment of infinity is ridiculous, but treatments exist in our head and not in the universe. The universe did exist for an infinite time, but us humans have chosen to begin counting from a certain point, which is why an infinite past is possible...

hello flyingpig.the figure is ok.but you did not mention whether the 3 contact surfaces are frictionless or not.if the surfaces are also frictionless: consider m3 first.the forces on it are its weight and the reaction offered by m2.thats all.there is no other force on it.these 2 act in the same...

thank you very much rock.freak667.it is very clear using the formula.but can you explain it physically?i mean by taking a practical example like a cylinder or airfoil?

Homework Statement is the drag on an airplane dependent on its weight? Homework Equations The Attempt at a Solution it was told that the drag depends on lift and the lift,on weight,in turn.but i am unable to comprehend it physically.