I had a look at a huge windmill and was wondering how fast the blades are spinning. Obviously, the distance the blades make is different on the outside than on the inside. Is the speed of a rotating object always measured in rpm and not in mph?
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There are some applications where you might want to know how fast the blades are moving, in that case you would use the outer most part. You can calculate it very easily if you know the rpm and radius of the windmill or whatever you are measuring.
If you want the speed of the object you have to measure in rpm. You can only measure in kph if you want to measure the speed of a surface on the object (e.g. the rotational speed at the equator of the earth)
Angular velocity is the technical term for rotational speed not expressed in RPM.
Angular velocity is usually stated in radians per second (rads^-1 ), there being 2.pi radians in a complete circle.
Some conversion function is required (if desired) to convert to degrees.
Angular velocity is the technical term for rotational speed not expressed in RPM.
Angular velocity is usually stated in radians per second (rads^-1 ), there being 2.pi radians in a complete circle.
Some conversion function is required (if desired) to convert to degrees.
If you want the speed of the object you have to measure in rpm. You can only measure in kph if you want to measure the speed of a surface on the object (e.g. the rotational speed at the equator of the earth)
There are some applications where you might want to know how fast the blades are moving, in that case you would use the outer most part. You can calculate it very easily if you know the rpm and radius of the windmill or whatever you are measuring.
There are some applications where you might want to know how fast the blades are moving, in that case you would use the outer most part. You can calculate it very easily if you know the rpm and radius of the windmill or whatever you are measuring.
Angular velocity is the technical term for rotational speed not expressed in RPM.
Angular velocity is usually stated in radians per second (rads^-1 ), there being 2.pi radians in a complete circle.
Some conversion function is required (if desired) to convert to degrees.
The tangential speed of something moving at an angular speed of w at a given point that is a distance r away from the center is v = wr.
So for example, a windmill spinning at 10rpm = 20pi rad/min would have a tangential speed of 100pi feet per minute = 3.6mph at a distance of 5 feet from the center (v = 10rpm x 2pi rad / rev x 5 feet = 100pi feet per minute).
RPM is revolutions per minute. When talking about the rotational speed of an object you’re going to be counting its revolutions, the only question then is what relative time frame you’re interested in.
>Obviously, the distance the blades make is different on the outside than on the inside.
Since RPM measures angular momentum–how many many times the object rotates in a minute–the length of the blades is not really a factor. The axel that turns the blades will turn it at the same speed no matter how long the blades are.
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