8,034 reputation
1728
bio website en.wikipedia.org/wiki/…
location United States
age 70
visits member for 3 years, 6 months
seen 5 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.


Jan
14
comment Problem regarding Archimedes Principle
It's a spring-mass-dashpot system (ignoring the dashpot). You can figure out the amount of mass, and you can figure out the spring constant (dForce/dY). Then look up the equation.
Jan
9
comment Turning an Airplane. What actually causes the circular motion in a banked (roll) turn?
@David: Your instinct is right. The tail acts as a weather-vane, which is the same as saying if the fuselage gets sideways to the relative wind, the tail (vertical stabilizer) feels that wind, creating a torque to turn the craft's nose into the wind. (Losing that tail is a good way to crash, because then nothing can stop the plane from going sideways.)
Jan
6
comment Different sized pneumatic Pistons
@TwoShorts_: I don't know what else to say. At the same pressure, force is proportional to area.
Jan
6
comment Turning an Airplane. What actually causes the circular motion in a banked (roll) turn?
@David: Neither. When you ride a bicycle in a circle, what causes the turn? It is the fact that you are leaning. That creates a sideways force. If there is a sideways force, there is no way you can go in a straight line - you have to turn. Banking an airplane and leaning a bicycle are the same thing. All the tail does is keep you pointing in the direction of travel.
Jan
6
answered What are the preferred height and diameter proportions for a rocket model?
Jan
6
answered Different sized pneumatic Pistons
Jan
6
comment Different sized pneumatic Pistons
Well then you can answer it yourself. Just suppose one piston has a surface area of 1 square centimeter, and the other is the size of a football field, and the air pressure on each one is the same per square centimeter. Suppose each one is actually a suction cup. Which would be harder to lift?
Jan
6
comment Different sized pneumatic Pistons
You mean with different area? Force is pressure times area.
Jan
5
answered Dropping Objects of Different Masses
Jan
4
awarded  Guru
Dec
30
comment Is there a way to convert CFM (rate of air moved) to kilograms of lift generated?
Force is momentum per unit time, so it's not just the mass of air moved, it is mass times the change in velocity.
Dec
26
answered A sees B's clock running slow and B sees A's clock running slow?
Dec
16
comment If an airplane is flying sideways, is it in free fall?
@Vivek: There's a maneuver called a knife edge where the wings are at 90 degrees to the ground. What the rudder does is put the fuselage sideways to the wind, generating the lift that holds the aircraft against gravity. Generally any such use of the rudder is called a slip or skid.
Dec
16
comment If an airplane is flying sideways, is it in free fall?
@Vivek: Yes, but would you call it free-fall? The pilot could be pulling 4G or more in that horizontal direction.
Dec
16
answered If an airplane is flying sideways, is it in free fall?
Dec
15
comment Can the weight of a bird be measured, considering air friction?
@Santhi: It comes out as extra air pressure on the bottom of the box. The wings get lift by pushing air downward, which hits the bottom of the box, which pushes the air back up so it stays in the box. That means the bottom of the box is feeling more pressure.
Dec
14
revised Calculate speed from accelerometer
added 3 characters in body
Dec
11
comment Does juggling faster less work then juggling slower?
Before you hoist a ball to a height, it falls into your hand from the same height, so in principle it takes zero work for any height. So it all depends on how efficient your muscles and joints are.
Dec
10
comment Where can I get fluidics components?
Excellent question, though some may think it is off-topic for physics. If I were you, I would start thinking about 3-d printers.
Dec
10
revised height of dam to allow certain flow rate
added 153 characters in body