{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}


Let us 12 find the moment of inertia about the y axis

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ass. Each such element of mass may be viewed as a element point mass with its individual position vector. Also, at the high school, we work with easy examples where a cross-section of the solid is uniform about an axis or at least symmetric about an axis. The moment of iner tia I i s defined as the measure of the tendenc y to tendency m oment t endenc otate r otate of a rigid body. About an axis A : IA = the axial moment of iner tia. a xial About a point P : I P = the polar moment of iner tia. p olar 193 y x (0,0) 43210987654321 43210987654321 43210987654321 43210987654321 43210987654321 (0,0) 54321 54321 54321 54321 54321 54321 54321 54321 54321 54321 54321 54321 54321 54321 y x lesser tendency to rotate about x-axis tendency greater tendency to rotate about x-axis tendency In the diagrams above the same brick of uniform density, depending on its orientation tendency rota otate orienta tion , has a different tendenc y to r ota te o r moment of iner tia t endenc m oment about the x-axis. It is impor tant to note that the brick is not in motion. The brick is at rest or in a state of iner tia . Therefore the moment of iner tia i ner m oment of a rigid body depends only on the orientation o r distance of the individual o rientation mas elements of ma ss f rom the axis or point of rotation. Measures may be formulated in different ways. Whatever be the measure, it should give a sense and propor tion of the entity being measured. Thus the formula for the moment of iner tia a bout an axis is defined as: m oment IA = (mass) . (square of perpendicular distance to the axis of rotation) This has the advantage of taking into account the orientation without being o rientation affected by which side of the axis, negative or positive, the rigid body is positioned or located. The quantity I c an be used directly in the equation of the kinetic energy of rotation. The moment of iner tia is always a positive m oment quantity. The measure of the tendenc y to r otate does not specify or include tendency rota otate t endenc the direction of...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online