If we are considering the semi circular wire of mass m to have a relatively small cross sectional radius, r compared to radius of the semi circular arc, R
And that we are considering the semi circular wire to lie in a xy plane. The mass moment of inertia taken about the z-axis (perpendicular to the plane) located at the cg position will be.
Izz=m*(R^2)*(PI-(4/PI))/PI
I did a check of this calculation with the way Catia calculated the same property. And the difference was found to be 0.03% When using the following geometry.
density=0.000001kgmm^3
Semi circular wire Radius R =60mm
cross sectional radius of wire = 1mm
results from Catia
V=592.176mm^3
m=0.000592176kg
Izz=1.268159kgmm^2
hand calculated results
V=592.176mm^3
m=0.000592176kg
Izz=1.267835kgmm^2
% difference [((1.268159)-(1.267835))/(1.267835)]*100=0.03%
Please carry out a check on the Izz calc. I determined it from 1st principles, so I may of made a mistake
Since, a steel wire is bent into a semi circular arc ,the new magnetic moment will be M
Inertia is a measure of how resistant an object's motion is to changing that motion, and is related to the mass of an object. Increase mass and inertia increases; decrease mass and inertia decreases. For an object to have greater inertia, it must therefore have greater mass. Semi- trucks are very massive vehicles, much more than others normally found, so they will have more inertia than anything else driven on roads. An average car or light truck might have a mass of 1 to 2 tonnes; semis usually have many tens of tonnes mass.
Don't know what the textbooks might tell you but I think this list of moments of inertia is rather comprehensive: rectangle circle cylinder hollow cylinder i beam triangle rod square disk area mass sphere hoop rotational t section ring shaft semi circle But these are moments of inertia. Not clear what you mean by moment of "force." Of course there is a force associated with moments of inertia. And that's the force F that is turning the object that has the inertia. In general that force is F = Ia where I is the moment of inertia and a is angular acceleration of the object.
Basically you need to do an integration, multiplying each mass point by its x-coordinate. Finally you divide by the total mass. Similarly for the y-coordinate.
bbishan
help me :'(
It is known as a semi-circular protractor.
There are two laws about inertia. The First Law has no formula. It is just a statement that says "an object will continue at constant velocity ,or at rest, until a net force acts on it". This property that requires a force to change its state of motion (or rest) is called the object's "inertia". The Second Law is a formula that describes how an object will move when a net force acts on it. The formula is F = ma. Where, F, is the force and , a , is the objects acceleration. And , m , is the objects mass, which is a measure of the object's inertia. So you could write the formula as a = F/m and in this way you see if the object's mass (inertia) is increased then in order to get the same acceleration you must increase the force. These two laws describe how an object's inertia ,or mass, resists changes in its motion.
semi-circular canals
They are the organ of balance.
Half a torus - a donut cut into a semi-circular disc.
help Gia Katie hellp me!!