Recent content by greendog77

Typically physics problems like this will not factor in such a vague condition. Usually we ignore parts of the problem that are not focused on by the text. In this case, we ignore the helicopter to focus on the rope. Also, several conditions can offset the theory. 1. The helicopter is...

no, you are not supposed to take into account the downdraft of air.

The magnitude of tension does get greater the higher up the point is, but there are two tension forces: one upwards, and one downwards. The tension forces cancel out, such that the net tension force is up along the rope, of constant magnitude. I can work this out more rigorously for you if you...

Well I understand it's extremely small, but after a long amount of time it would happen. That being said, it just seems to me that the 2nd Law is not 100% rigorous, that it's statistical like stevendaryl said?

I've always been slightly confused by the Second Law of Thermo. For example, with Maxwell's Demon, where a demon controls the partition between two gas chambers to select all the fast moving particles into one chamber, the Second Law is not violated because the demon's actions and thought...

sorry, i meant that the phase shift of the emerging waves should have the same value?

I've learned about path difference and all the basic concepts about waves, so I think it's a matter of actually applying them to this method I've never heard about. Based on what you've told me it sounds like what I should do is equate the path difference of the plane waves to zero when they...

hm no i haven't. what is the method?

I've learned about phase shifts but not graded index materials. To me that sounds like a method to solve a specific set of similar problems?

in that case the emerging rays would all be parallel, correct?

Homework Statement The index of refraction of glass can be increased by diffusing in impurities. It is then possible to make a lens of constant thickness. Given a disk of radius a and thickness d, find the radial variation of the index of refraction, n(r), which will produce a lens with...

The time t on the clocks in S would have read simply -L/v. The spacetime coordinate of the explosion in the S frame would thus be (-L/v, -L). This means that in S', the coordinate of the explosion would be (\gamma(-L/v+vL/c^2),\gamma(-L+L)) = (\gamma(-L/v+vL/c^2),0). This means that the time...

Homework Statement A spaceship is approaching a planet at a speed v. Suddenly, the spaceship explodes and releases a sphere of photons traveling outward as seen in the spaceship frame. The explosion occurs in the planet frame when the spaceship is a distance L away from the planet. In the...

Thank you all! This makes complete sense to me now.

I thought the four base fictitious forces were centrifugal, linear, coriolis, and azimuthal. So does that mean fictitious forces don't necessarily have to fall within those categories? Under what circumstances do they fall under those categories? You mentioned the ball is constrained to have the...