7,738 reputation
1628
bio website en.wikipedia.org/wiki/…
location United States
age 70
visits member for 3 years, 3 months
seen 22 hours ago

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.


Oct
23
comment Intuitive meaning of a special case of the Bernoulli equation
+ @JánLalinský: The only thing that can accelerate a fluid is pressure, providing force that works through a distance, producing kinetic energy in the fluid. I think that's what Kyle is saying.
Oct
22
comment finding equation of a water droplet
Aren't water droplets like rain basically spheres?
Oct
20
comment Speed of sound and Break the sound barrier
@A.khalaf: This is right, and the reason for the conical cloud is the sudden pressure and temperature drop (in humid air) behind the shock wave.
Oct
18
awarded  Nice Answer
Oct
12
comment Benefits of rear spoiler in cars
It helps it accelerate off the showroom floor.
Oct
11
revised How does a knife cut things at the atomic level?
added 597 characters in body
Oct
10
comment If i had a aero-nautical object
The California Condor has a 10-foot (length, not body part :) wingspan and weighs up to 26 pounds (weight, not money:). So if the wind is about 25% faster than a condor flies, it might work.
Oct
10
comment What is the power in this circuit if the voltage is doubled?
@Floris: You're right. I was doing back-of-the-hand physics.
Oct
9
comment What is the power in this circuit if the voltage is doubled?
Right. If you double the voltage across a resistor, that doubles the current. Double voltage times double current - four times power. If you're in the U.S. and you take a 100-watt light bulb built for 110 volts, and accidentally connect it to 220 volts, what happens? 400 watts - POP!
Oct
1
comment What stored charges do in a capacitor?
If the fan motor has brushes, the capacitor can prevent arcing.
Oct
1
awarded  Nice Answer
Oct
1
answered Why do rockets jettison fuel tanks?
Sep
30
awarded  Explainer
Sep
30
answered How long does it take to equalize pressure of two gas containers?
Sep
29
comment What causes a spacecraft entering the atmosphere to catch fire?
Check Wikipedia.
Sep
29
comment When two objects roll down an incline, does the velocity increase?
Suppose their radii are 1cm and 2cm. Since it says they roll together, they have to have the same tangential velocity (i.e. zero at the point of contact, and 2V at the opposite point. The "axle system" must be one that turns the small one at twice the angular velocity (with gears). Since centripetal acceleration if V/R^2, the small one has 4 times the acceleration.
Sep
26
comment How does train back draft work
+ And if the train is long, it carries air with it along the sides, lowering the pressure, so pulling in careless creatures.
Sep
25
comment Time for water levels to equalize
Pouring in the quantity of water will start a surface wave, which travels at a speed depending on the wavelength (longer = faster), and as @John said, that depends on the depth. After a couple circumnavigations, the wave will dissipate, leaving the water deeper. Not a simple problem.
Sep
24
comment Modeling wall's behaviour
It's pretty simple. The tree is going to grow, and the wall is no match for it.
Sep
24
comment Fill and drain tank (same time)
Forget ODEs and fancy theorems. $q_1 - q_2$ is the rate at which the volume of liquid increases, and the volume is height times area $A$. Unless $q_2$ is not constant.