Recent content by recon

Thank you, Gokul. I have to say that my early participation and interaction with members of PF inspired me to study Physics to a greater depth than what was required at school. :biggrin: Studying beyond what is required by the school curriculum is virtually unheard of in my country, so I...

I'm from Brunei, and we don't yet have a national olympiad for physics. This year I was very lucky to be selected to be part of the first Brunei team to the IPhO in Singapore. Each school from our little nation was asked to nominate two of their best physics students, and we all took a...

I thought that the pressure that the air bubble exerts on both water columns was the same. Perhaps I misunderstand what you mean by unequal pressure. There is a height difference in the ends of each of the two water columns, so this provides the pressure to oppose the pressure in the air...

P = P_0 + h \rho g I don't know...

Since no one in the Introductory Physics forum can help me, can/should this be moved somewhere else?

Someone please help. This is a Challenge Problem from a textbook, so it's not supposed to be too trivial. Or can someone point out something obvious that I've been missing? :(

Well, I think that the water level in the two opposite tubes will be different, because the volume of water in the two separate parts of the tube (separated by the air bubble) may be different.

"It is the practice of carpenters herabouts, when laying out and leveling up the foundations of relatively long buildings, to use a garden hose filled with water, with glass tubes 10 to 12 inches long thrust into the ends of the hose. The theory is that water, seeking a common level, will be the...

A question from my HW on Alternating Currents: "When a domestic electric heater is operated from a 240 V a.c. supply, an r.m.s. current of 8.0 A flows. Assuming the heater is purely resistive, calculate its resistance, mean power and maximum instantaneous power. " I don't know what is meant...

My high school physics class does not cover non-inertial frames, but anyway I think I understand now, and I'll try and read up on it later. Thank you very much! :)

Can someone explain why there is a net torque about the point of contact of the bicycle with the ground?

The following is a problem from the examples section of my school textbook, so it is accompanied by a full solution. However, I do not fully understand it and need your guidance in clearing my doubts. http://img151.imageshack.us/img151/7024/picture30rr.jpg "A cyclist is moving at speed v...

I know \frac{dv}{dt} = \frac{GM}{r^2} but I can't figure out how this may be used to obtain v as a function of r. How is it possible to solve the equation \frac{d^{2}r}{dt^2}=\frac{GM}{(R+r)^2}, where R is the radius of the Earth? I have not had much calculus yet, so I have not touched on...

If it takes an object at distance x from the surface of the Earth 17.5 hours to fall from space onto the surface of the Earth, how can we calculate x? The object initially has zero speed. I find this question hard because I've only done problems involving acceleration as a function of time...

I am interested in mathematics and physics, but I don't really know what I should do in University. I'm just about to start my final year in high school, and my school's career counsellor has asked us to think of what we might like to major in. Are we really expected to be able to make an...