Tagged Questions
1
vote
0answers
50 views
effect of internal forces to a glider's descent
This is a continuation of a previous question, with more thinking applied, thanks to a helpful comment.
Imagine a glider is airborne in a breezeless sky. The glider is 3 KM high, is traveling at 100 ...
0
votes
0answers
28 views
effect of internal force to a glider's descent [closed]
Imagine a glider is airborne in a breezeless sky. The glider is 3 KM high, is traveling at 100 KM / hr, and is descending at a constant rate of 10 m per min. The glider weighs 200 kg. The sole ...
12
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1answer
414 views
Do modern Formula One cars produce enough down-force to drive upside-down?
For example, if they were driving at top speed through a long tunnel, could they transition to and stay on the ceiling?
0
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1answer
357 views
Calculation for force generated by a rotating rectangular blade
When trying to calculate the lift force generated by a simple rectangular blade, I've found the following equation: $$F = \omega^2 L^2 l\rho\sin^2\phi$$ in which $\omega$ is the angular velocity, $L$ ...
0
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1answer
339 views
Ping pong ball levitation control system question, modeling as a damper?
I am building a control system to levitate a ping pong ball at a given height in a clear plastic tube using an arduino and implementing PID control.
I have to come up with a transfer function... I am ...
1
vote
1answer
1k views
Will a lighter car have a higher top speed than a heavier car with an equal power engine?
If I have a car (with a particular engine) optimized (shape & weight distribution-wise) for attaining the top speeds possible, and I put that engine into a car which is heavier (but otherwise the ...
3
votes
3answers
333 views
Why trimming the mainsail gives a larger torque to head up
I am learning sailing on a 5m catamaran (Nacra 5).
I am familiar with basic aerodynamics and the physics of the sail and keel.
We learned that when sailing closed hauled, too tight a mainsail tends ...
10
votes
4answers
808 views
Helicopter in an Elevator
You buy one of those remote control toy helicopters. You bring it into an elevator. The elevator goes up. Does the helicopter hit the floor or does the floor of the elevator push the air up into the ...
2
votes
3answers
190 views
Making a “heavier-than-air” craft float
How big would a hollow rigid object need to be to float, (not in water but in air) if all of the air was vacuumed out and the container sealed?
12
votes
4answers
895 views
How to sail downwind faster than the wind?
Recently a group set a record for sailing a wind-powered land vehicle directly down wind, and a speed faster than wind speed. Wikipedia has a page talking about it, but it doesn't explain exactly how ...
