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location New England (USA)
age 53
visits member for 2 years
seen 35 mins 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 by 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.


8h
comment What could cause a 30 k g acceleration?
I am guessing that the manufacturer has a test rig that can go up to 30 k g... in fact, there is an article here describing several such methods including a drop test that produces 30k g. The key is to make the impact "short" (30 s drop, 1 ms stop = 30 k g if $F\Delta t$ is to be believed. With a "shock amplifier", the drop can be less).
8h
comment Why, when one opens 1 car window, does that noise occur?
"You don't have permission..." - link broken?
8h
answered Car window vibrating noise
16h
comment Slingshot Energy into traveled distance
Slingshot relaxed = 0 J. With object supported, it has some energy stored ($\frac12 k x_0^2$). Fully stretched to $x_1$ it may have 1000 J stored. Is that $\frac12 k(x_1^2-x_0^2)$ or $\frac12 k x_1^2$? Because it is quite possible that the energy stored in the "object supported" state is already 1000 J... at which point you can't shoot the object at all.
19h
comment Can a nozzle increase the thrust of a water rocket?
What are you keeping constant? If you make the nozzle smaller and keep mass flow the same you must increase the pressure. If you keep pressure the same, mass flow must drop; which is it?
19h
comment Slingshot Energy into traveled distance
If the sling shot has 1000J energy when extended, then it can lift the mass 1 m from that point. If the rubber was extended 0.2 m, the object will "fly" 0.8 m. This is further complicated by the question whether "equilibrium position" is the position of the object testing against (and extending) the sling. Is the energy stored at that point included in your 1000 J?
21h
comment Mechanism for visible light frequency mixing in storm clouds
@CJRS - no worries, we all do it. That's why this is a "community"...
21h
comment Mechanism for visible light frequency mixing in storm clouds
There is at least one typo in your expression - should it not be $(\omega_1 + \omega_2)t/2$ for one of the $\cos$ terms? And doesn't frequency mixing require a nonlinear response of at least one element? Can you explain what element that is?
1d
comment Why we can't define energy in accelerating frame?
No I didn't say that. If you consider the fictitious forces and the work they do, energy is conserved. But the "fuel" for these fictitious forces is coming from outside your system. I don't think I can explain this very well...
1d
comment Why we can't define energy in accelerating frame?
When you observe something in an accelerating frame, 'fictitous" forces appear (Coriolis and Centrifugal forces are examples for the rotating frame). That apparent force can do apparent work and preserves energy.
1d
answered how to calculate flow rate of gas thru a tapered nozzle
1d
comment how to calculate flow rate of gas thru a tapered nozzle
Are you assuming that enough heat is available in the environment to keep the pressurized contents of the cylinder at ambient temperature?
1d
comment Why we can't define energy in accelerating frame?
I am not sure why you say "energy is not defined in an accelerating frame". I looked at your old question and can't see how that follows.
1d
comment Why the rotational speed of a simple single-coil DC motor will increase as the number of turns in the coil increases?
Does your motor have a lot of friction? What is the relationship you observed between number of turns and speed?
1d
comment Is the sum of mass of all planets in our solar system is 40% the mass of the Sun?
See also physics.stackexchange.com/a/195468/26969
1d
comment How is power of a water pump related to amount of water delivered from pipe?
Yes it is. See if you can understand this link - although it states the $v^2$ relationship as a given. Also, this earlier answer talks a bit more about fluid flow profiles - but while it addresses a different aspect, there may be some insights there for you.
1d
answered How is power of a water pump related to amount of water delivered from pipe?
1d
comment Which makes an electromagnet stronger? AC or DC?
@UnicornsAreVeryVeryYummy - I took the liberty of uncapping the question...
1d
comment Which makes an electromagnet stronger? AC or DC?
Please stop using all caps. You need to define how you compare your AC and DC if you want to get a sensible answer. There are times during the AC cycle when there is no current, and the electromagnet has zero force.
1d
revised Which makes an electromagnet stronger? AC or DC?
removed the shouting