13. Rotational Inertia & Energy
Intro to Moment of Inertia
1PRACTICE PROBLEM
A non-uniform thin spoke has a total length L. Its mass per unit length depends on the position x measured from the left end and is described by the function dm/dx = Ax where A has units kg/m2. i) Determine its moment of inertia about a perpendicular axis through its left end (x = 0) using I = ∫r2dm. ii) Does its moment of inertia differ from the moment of inertia of a uniform spoke?
A non-uniform thin spoke has a total length L. Its mass per unit length depends on the position x measured from the left end and is described by the function dm/dx = Ax where A has units kg/m2. i) Determine its moment of inertia about a perpendicular axis through its left end (x = 0) using I = ∫r2dm. ii) Does its moment of inertia differ from the moment of inertia of a uniform spoke?
ANSWERS OPTIONS
A
i) (1/2)ML2 ii) It is greater than the moment of inertia of a uniform spoke
B
i) (1/4)ML2 ii) It is greater than the moment of inertia of a uniform spoke
C
i) (1/3)ML2 ii) It is the same as the moment of inertia of a uniform spoke
D
i) (1/6)ML2 ii) It is less than the moment of inertia of a uniform spoke
E
i) ML2 ii) It is greater than the moment of inertia of a uniform spoke
F
i) (1/5)ML2 ii) It is less than the moment of inertia of a uniform spoke