You spend some time experimenting with a baseball bat, and eventually you are able to balance the bat on a single finger. A friend notices this, and makes the following claim:
“It looks like the balancing point isn’t in the middle of the bat—it’s a little closer to the thicker end of the bat. That balancing point must be the location where half the bat’s mass is on the left and half the bat’s mass is on the right.”
How would you respond to your friend’s claim? Is your friend’s claim correct, partially correct, or incorrect?
Explanation13.7.2.Inertia Statements.
Which of the following statements concerning the moment of inertia I are false? Explain your reasoning.
I may be expressed in units of \(\mathrm{~kg m^2}\)
I depends on the angular acceleration of the object as it rotates
I depends on the location of the rotation axis relative to the particles that make up the object.
I depends on the orientation of the rotation axis relative to the particles that make up the object.
Answer.
B.
SubsectionA*R*C*S Practice
A*R*C*S13.7.3.Moment of Inertia Shift.
Calculate the moment of inertia by direct integration of a thin rod of mass \(M\) and length \(L\) about an axis through the rod at \(L/3\text{,}\) as shown below. Check your answer with the parallel-axis theorem.
Figure13.7.1.
A*R*C*S13.7.4.Center of Mass.
You have a triangular piece of metal with total mass \(M\text{,}\) base length \(L\text{,}\) and height \(H\text{.}\) You know the mass density is uniform. Find the center of mass of the piece of metal.
A*R*C*S13.7.5.Moment of Inertia of a Tennis Ball.
A tennis ball can be modeled as a spherical shell with total mass \(M\) concentrated at radius \(R\text{.}\) Calculate the moment of inertia about an axis passing through the center of the tennis ball.
ReferencesReferences
[1]
Inertia Statements provided by BoxSand: https://boxsand.physics.oregonstate.edu/welcome.
