Recent content by lowea001

Hello, I've recently been admitted to the MSc QFFF program at Imperial College London for the 2019-2020 year and am seeking advice regarding possible career paths/was wondering if anyone is in a similar situation. My end goal is to do a PhD in the United States since (for non-academic reasons)...

EDIT: I realize now that I have fundamentally misunderstood a crucial aspect of deriving the Bell inequality for this case which is the existence of the third axis. The setup of the problem did state that the axes were chosen at random. Therefore I can't just look at the possibility of choosing...

Haha five seconds after posting this I found my own mistake but I have decided to leave this up here as a demonstration of how the approaches eventually correspond to the same answer: my mistake was in evaluating the integral \int_{a}^{d/2}\left(\frac{1}{r}+\frac{1}{d-r}\right)dr =...

Homework Statement Consider two long parallel wires each of radius a with a separation distance d between them. They carry current I in opposite directions. Calculate the magnetic flux through a section of length l, ignoring magnetic field inside the wires. My confusion lies in trying to...

Based on my current understanding of the problem I do not see this following derivation as valid, although this is what was given in my course notes. Although this particular example is from an undergraduate physics course this is not a homework problem: I'm confused about the underlying...

Thanks for your help guys. I have a much better understanding of the problem now (it's kinda neat actually) but the answer given in the solution page is v_0 = Rw, which I'm not sure how to obtain.

Hiya, sorry about that. It wasn't going down the right path so I tried it again below. Thanks. Overthinking can be the worst. However, I'm still doing something wrong I believe. This is my attempt: \frac{\mathrm{d^2} x}{\mathrm{d} t^2} = \frac{-g}{r} xTherefore the solution is of type: x =...

Homework Statement [/B] Two cities are connected by a straight underground tunnel, as shown in the diagram. A train starting from rest travels between the two cities powered only by the gravitational force of the Earth, F = - \frac{mgr}{R}. Find the time t_1 taken to travel between the two...

Doesn't that just give me equation 2 again?

This is what I did to get equation 2. Separable variables in this case gives me an equation for x, not v, no? I mean, the question is solved but as you said I should be (and am) just as interested in the method. So if a one line solution exists, I'd like that.

v = \frac{ft + V}{1+bx} \ (1) \\ Using \ quotient \ rule \ and \ asserting \ acceleration \ can \ be \ zero: \\ \frac{dv}{dt} = \frac{f(1+bx) - \frac{dx}{dt}(ft+V)}{(1+bx)^2} \\ 0 = \frac{f}{1+bx} - \frac{bv(ft + V)}{(1 + bx)^2} \\ 0 = \frac{f - bv^2}{1 + bx} \\ 0 = f - bv^2 \\ v =...

Also, just out of interest, apparently as t -> infinity, v -> a constant. Sounds fun, but how can I show that?

Thank you so much! Finally figured it out.

Oh don't put in the expression for x? If I partial differentiate the expression with respect to time is that still the acceleration regardless of x? Or can I just treat it as a constant somehow? (Sorry I'm a calculus noob).

Yes M is a constant, its initial mass, but its mass is always changing and at any position x is M (1+bx). Therefore gravity remains constant according to the wording of the question I.e. dp/dt is a constant fM (I know it doesn't make sense but if you replace gravity with contant force it does)...