Hi, I just have a related question on the energies of a pendulum, and am not looking to start a new thread (unless mod feels it should be).
F the potential energy and kinetic energy are given by
U(θ)=mgLθ )
K(θ)= mgL(cosθmax-cosθ)
*Since kinetic energy simply is difference between...
Thanks for the replies. snorkack, I understand what you mean about densest sphere packing of particles. My question was how does this change, and differ, in the transition from solid to gas? My original understanding (or rather misconception) is that particles in the solid move away from each...
I was thinking of a substance I could use to describe particle arrangement in solid/liquid/gas phases to school kids, and after realising water would be bad to use (since the liquid is denser than solid), I thought of using metal elements since they can exist in all phases.
Basically the...
Hi. This isn't exactly like the previous thread and not a homework problem. I'd just like to check the validity of my solution. It concerns the relation between a discrete and continuous probability distribution.
The problem:
A player inserts a bullet into a 6-chamber revolver. He then spins...
That is rather obvious, can't believe I missed it. Anyway putting in A=R+r I get the sum of the masses to be 1.78 (solar masses).
It makes sense to put the slower, heavier star on the inside and faster, smaller one on the outside. Not sure of the principle behind it, but if their masses are...
In general terms: let R is the larger radii and r the smaller one. Their maximum distance apart is R+r (opposite side), and minimum R-r (same side) which average to R. However in this problem the stars orbit the same period, sweeping out the same angle per time, meaning the separation is...
There's only 2 concentric circles, the centre of mass (G) is just a point about which the stars orbit.
But I suppose with your idea I can relate the period with the circumference from the orbital speed:
v = \frac{2\pi r}{T}
So for star A, and taking T in years (17.5days = 7/146 years) and 1km/s...
Application of the Doppler effect and Kepler's 3rd law
Homework Statement
(*This isn't the exact wording from a textbook, just as I had copied it down)
An eclipsing binary star system containing stars A and B in concentric orbits (about their common centre of mass) has it's maximum red- and...
Hi everyone, I just started an introductory course in astronomy and we've covered co-ordinate systems on the celestial sphere. I haven't seen any threads like these so I apologize if it's in the wrong section.
In this very crude drawing of the northern celestial sphere, the observer is...
Although I don't really see the need to choose an \epsilon, I understand why for clarity it makes sense to chose one. I thought that proving that there exists some k for which an is bounded would be sufficient, but I see now one has to consider a set of {a_n : n < k} then use the fact that the...
Homework Statement
Prove that every convergent sequence is bounded.
Homework Equations
Definition of \lim_{n \to +\infty} a_n = L
\forall \epsilon > 0, \exists k \in \mathbb{R} \; s.t \; \forall n \in \mathbb{N}, n \geq k, \; |a_n - L| < \epsilon
Definition of a bounded sequence: A...
Is it only the measurements that are relative, or the actual events? If t is the time for the traveller (proper time) and t' is for the observer, t' =71t . Then is it correct to say that for every heartbeat of the traveller, the observer's experiences 71 heartbeats (or is it other way ><). This...
If then Sun had to instantaneously vanish (it's energy, light, mass) how long would it take for Earth to feel the gravitational effect (ie. change orbit) and how exactly would the orbit change?
SR limits speeds to that of light. Sunlight takes about 8 minutes to reach Earth, but is that how...
Strange thing about SR is I understand it one second, then confuse it another :/
I know it's impossible to reach the speed of light, but hypothetically if one did, then they could 'freeze time' of the frame with respect to which they are moving.
Okay suppose his speed is just 0.9999c, so then...
First check that I am formulating it correctly:
Sam and Pam are identical twins.
In 2000, Sam departs on a 20-light year journey at the speed of light (hypothetically). When she returns (travelling a total of 40-light years) she finds Pam in 2040, being 40 years older than she is (physically...