15,539 reputation
23158
bio website
location New England (USA)
age 52
visits member for 1 year, 3 months
seen 5 hours ago

I have formal training in physics, but tend to approach it very intuitively; I prefer estimation over exact calculation, principles over details. I believe many problems can be solved my making a careful sketch. Label your axes, and don't use insignificant digits.

I visit this site in the hope of sharing my enthusiasm and occasional insights with others.


5h
comment Dry Ice Sublimation time, practical calculations
Are those the inner or outer dimensions of the box? What is the heat capacity of the balls (what material). Both these things affect the answer. Please clarify.
19h
comment what could generate a high-pitched whine in electronics where the frequency depends on the current?
This doesn't require resonance. OP stated the pitch is rising continuously and there are harmonics. That is entirely consistent with a system that has the components I describe including a "badly designed speaker" that concerts currents into mechanical vibrations. If the driving force was a sinusoidal wave you would see fewer harmonic components. But a switching supply isn't a "distorted sine wave"- it is intended to be a square wave.
23h
answered what could generate a high-pitched whine in electronics where the frequency depends on the current?
1d
comment Intuitive explanation of Huygens construction?
Your statement "any other wavelet created..." Is false. Look at blue wave 3. After $1/f$ it has reached position 3 on the surface - but the wavelet drawn at the intersection of 2 and the boundary has not yet reached that point. This is precisely why the wave is refracted. The convenience comes from ability to compute wave length (and thus spacing) easily - even as it varies from one medium to another.
1d
comment Intuitive explanation of Huygens construction?
Separating them by one wavelength is just a convenience when you look at refraction - but when you use this kind of construction to analyze diffraction (e.g. Young's slits) then integer wavefronts (or half integer wavefronts) help you figure out where diffraction peaks will occur.
1d
comment Metal with the biggest positive and negative charge per atom (ion)
For the same amount of charge stored, the lighter atom results in a lighter battery or capacitor. And since you usually have batteries in portable devices, weight matters...
1d
comment Metal with the biggest positive and negative charge per atom (ion)
I suspect you are looking for ways to make these devices more efficient - but do keep in mind that you usually care about specific capacity - getting a charge of +1 from Li is more useful than getting +3 from a much heavier atom...
1d
revised Spherical mirror ray diagram question
added 356 characters in body
1d
comment Catapult projectile with different mass
What is the mass of the box vs the mass of the ball / balloon? There is no "magic formula" that simply works - you need to consider what is moving, and how fast, and how changes of mass of one component affect everything else. Without drawings etc I cannot comment. Your "typical" catapult may not be the same as mine.
1d
comment Catapult projectile with different mass
As @CuriousOne says, the answer will depend strongly on the type of catapult - there is no general equation that will "just work". If you can ignore gravity during launch (ball goes much higher than height of catapult) and you have a simple elastic, then $v_{balloon}\approx v_{ball}\sqrt{\frac{m_{ball}}{m_{balloon}}}$
1d
answered How to calculate magnitute of average acceleration?
1d
answered Catapult projectile with different mass
1d
revised Catapult projectile with different mass
added 13 characters in body; edited tags
2d
revised Why do electrons orbit protons?
added 1 character in body
2d
comment Intuitive explanation of Huygens construction?
You can have discontinuities at a boundary but otherwise yes.
2d
revised Intuitive explanation of Huygens construction?
added 1137 characters in body
2d
comment Intuitive explanation of Huygens construction?
You could consider that the numbers correspond to times - connecting all the wavefronts labeled "3" will show you where the wavefront is at time 3, etc. I think that is what you are saying as well...
2d
comment Why is it mandatory to lose energy to an opposing force?
I have some difficulty understanding the first line of your comment but I believe the answer is "yes, that's right".
2d
comment Is Photoelectric Effect continuous or discrete?
It would be "photo electric" effect but not "the" photoelectric effect...
2d
comment Plank stopping time (Continuation and Physical meaning)
That seems strange but it makes sense - that's exactly how simple harmonic notion works. Think about the motion of a pendulum - the time from the middle of the swing to the time it stops is independent of the amplitude (velocity at center) as long as the small angle approximation holds. Counterintuitive but true - you did well.