Tagged Questions
2
votes
2answers
112 views
Whats the anti-torque mechanism in horizontal take-off aircraft?
In most helicopters there is the anti-torque tail rotor to prevent the body from spinning in the opposite direction to the main rotor.
What's the equivalent mechanism in horizontal takeoff single ...
5
votes
1answer
153 views
Drag on a spinning ball in fluid
I am a physics newbie (high school level) and I am wondering what happens when a spherical object is spinning on the spot in a bunch of gas (no gravity here, just an imaginary physics sandbox).
Am I ...
2
votes
0answers
59 views
Fluid flow in a hollow spring(helix)
Liquid flowing in a long hollow spring(helix). Any effects on the flow rate etc when the spring is stretched or compressed?
When the stretching or compressing of spring is done at brisk speeds the ...
3
votes
2answers
348 views
Bernoulli's equation and reference frames
So I was thinking about this while driving home the other day.
I've never been quite clear on why when you drive with the windows down air rushes into your car. I thought this might be explained by ...
0
votes
1answer
138 views
By how much will water resistance and upthrust slows down a fully submerged object?
Consider the following example:
While running, I do work and I have a certain velocity and acceleration.
When I'm in a pool (my feet are touching the bottom), I do the same work but, I have less ...
2
votes
4answers
456 views
At same level do these two pipe lines give same pressure of water?
Provided that the two pipe lines are of same length, same material and in the same level, is the water pressure in both the layouts same or different?
PS: In 1st pipeline the turns are not ...
5
votes
1answer
135 views
Distance a curveball travels?
I've seen some discussions regarding the movement of a spinning object, say a curveball. However, all have been largely qualitative. I was wondering if anyone has seen or worked through a ...
0
votes
1answer
665 views
Is the static gauge pressure of a free jet always atmospheric?
Let's say I have a free jet of air leaving a pipe into the atmosphere. I know that the static gauge pressure at the pipe exit is equal to the atmospheric. But what about the static gauge pressure 10 ...
1
vote
1answer
165 views
Is the pressure at the outer hole on a pitot static tube equal to atmospheric pressure?
I'm looking at a pitot static tube question right now and I just need some clarification. There is the outer hole on the pitot static tube, not the hole that the air stream goes through, but the other ...
1
vote
0answers
109 views
How do I determine where the maximum air velocity around an object is?
I have a freestream of air directed at an object. Is there a way to find where the maximum air velcoty occurs with only having initial air speed and static pressure at the object?
0
votes
0answers
281 views
Calculating torque of actuators? [closed]
How do you calculate the torque of a brushless dc electric motor?
How do you calculate the torque of a hydraulic motor?
How do you calculate the push and pull force of a double acting hydraulic ...
0
votes
0answers
222 views
Which actuator is more effective: pneumatic, hydraulic, or electric? [closed]
For an system that amplifies strength by about two (press capacity of 400 lbs.), which would be the most practical, or the most compact?
A pneumatic system that uses air cylinders or air muscles,
A ...
4
votes
2answers
1k views
Shape of Fan Blades
How is the shape of the blades of an air fan determined? Trial and error, or is there a theory behind it? What are they trying to maximize, volume of air dislocated per rotation?
26
votes
10answers
2k views
Mechanics around a rail tank wagon
Some time ago I came across a problem which might be of interest to the physics.se, I think. The problem sounds like a homework problem, but I think it is not trivial (i am still thinking about it):
...
