6,281 reputation
1322
bio website en.wikipedia.org/wiki/…
location United States
age 69
visits member for 2 years, 7 months
seen yesterday

BS Mechanical Engr.
PhD CS(AI)
CS Prof (4yr)
Numerous consulting jobs.
15 yr at http://www.pharsight.com
Published book on CS & several articles
4 kids, 2 grand
Pilot(student)

P.S. The picture is a Beta-prime distribution. It shows the program speedup factors you can get if you see a problem twice in 2, 3, 4, and 5 samples.


Feb
25
comment No-slip condition when one fluid flows through another
yes............
Feb
21
comment Relationship between engine Speed at maximum power and torque
Power is the product of torque and RPM, so naturally they will occur at different speeds. You get to an RPM where if you increase the RPM by a little bit, the torque falls by a little bit, but the product of the two stays the same. Like at about 5.5k in your picture.
Feb
19
comment Where / what is the source of the force that causes refraction?
Photons have no mass. Their energy is not kinetic. It is a function only of their frequency.
Feb
19
comment Picking up audio using high speed video?
There is however this gadget that uses radio rather than light.
Feb
18
comment Pascal's Principle and hydraulic lift
@John: Right. My simplistic analogy is pushing against a spring. You can't exert a certain force against it without also compressing it.
Feb
15
comment How much weight can a person carry to avoid being blown over by wind?
It does get windy between the buildings in Boston (or anywhere). I would go with @Carl's suggestion of a cane, especially one that is adjustable and collapsible, and that has a strap or hook so you can free up both hands without dropping it. The trouble with a rolling bag is just that - it rolls, so it may not give as much stability as you'd like. Good luck. (Just thought of another possibility - a 4-wheel bag that you can lean on while it rolls - maybe?)
Feb
11
comment water in vacuum(or space) and temperature in space
Take a beaker of water out of the space station and remove the lid. First the water will float out, then it will boil away because of no pressure, and the vapor will fly away. If you kept it under pressure so it could not boil off, then it would either 1) get hot when the sun shone on it, or 2) get cold in the shade, because it would radiate its heat away to the sky, which is practically at absolute zero.
Feb
8
comment How can a fly be in the space of a roofless car, get out of the car space and get back in while the car is driving at the speed of 80mph?
Maybe relevant. My cousin is a long-time pilot. He has heard of people who wished to have their ashes spread from an airplane. What a mess! The dust blows everywhere and they have a big cleanup job.
Feb
6
comment Can you read and write a quantum state to a particle without collapsing its probability field?
Writing information to it before a computation is no problem. After it has started, you cannot touch it until it is finished, at which time you can read it. You may not get the right answer. You have to arrange the computation so that the right answer has an acceptably high probability.
Feb
6
revised Convective derivative of oscillating fluid with bulk motion?
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Feb
4
comment Calculate work done in an inclined plane
@mc8: Then you're not elevating it, right? So you're not putting in any potential energy. You might give it kinetic energy, if you push it and it just keeps on moving. That's when your F=ma comes into play.
Feb
3
comment Calculate work done in an inclined plane
@mc8: Glad you got it. You're welcome.
Feb
3
comment Calculate work done in an inclined plane
@mc8: Because the work done is the same whether it is done in one minute or in one millenium. In the frictionless case, the weight rises through a distance, increasing its potential energy, and that is the work done. Please figure out the rest of it yourself.
Feb
3
comment Calculate work done in an inclined plane
@mc8: because you're not accelerating. It's a simple balance of forces.
Feb
3
answered Calculate work done in an inclined plane
Feb
3
comment Calculate work done in an inclined plane
Draw a vector diagram of the forces, and use a smidge of trig.
Feb
3
comment Calculate work done in an inclined plane
Sounds like homework. Figure out the force if it is frictionless, then add in the friction force, multiply by distance. Forget F=ma - you figure out why.
Feb
2
comment Why does the blade height goes on decreasing in a multi-stage axial flow compressor?
+ Right. As the air is squeezed, its volume decreases.
Feb
2
revised When is the stress on an airplane the highest?
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Feb
2
revised When is the stress on an airplane the highest?
added 66 characters in body