All Questions
Tagged with inertia rotational-dynamics
33
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Why is the moment of inertia the rotational analog for mass and not inertia?
I've thought that both mass and the moment of inertia measure an object's inertia, one being in translational motion and the other in rotational motion. That has made complete sense to me, but in my ...
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Evolution of a rotating system in which mass continually leaks [closed]
this might be a trivial problem but me and a friend have failed to solve it. This is not homework, it actually relates to a book of mine but that is of no interest. Imagine the following;
Two masses $...
- 308
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Why the orientation of an object on Earth rotates with the rotation of earth? Is this due to friction?
The moon always faces toward Earth. That's because the moon rotates itself while revolving around the earth. This might be the result of tidal force for a long time, but what about objects on Earth? ...
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Why are the masses hanging from a pulley not considered in its moment of inertia?
My physics textbook showed a diagram of a pulley with mass with 2 blocks hanging from either side by a massless string. They calculated the moment of inertia by finding an approximation of the pulley ...
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How to find inertia tensor of a circular ring from angular momentum and velocity?
Consider a thin circular ring with radius $R$ and axis of rotation as shown in the figure. If $\vec{L}$ denotes angular momentum and $\vec{w}$ is the angular velocity then
$$\vec{L}=\begin{bmatrix} I_{...
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Which is true: objects keep spinning because of inertia, or objects keep spinning because of centripetal force?
I'm hoping any gravity or friction can be ignored.
I gather a spinning object is a non-inertial frame. I suppose that's because change of direction is acceleration. Continued acceleration requires ...
user326693
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Why is a larger force needed when you decrease the distance in regards of torque? [closed]
I think it's because of inertia.
- 107
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Why can we calculate moment of inertia, but not inertia?
I'm learning about rotational motion and the moment of inertia. Unlike inertia that I learned before, there is a formula to calculate rotational inertia. I'm having trouble understanding why it's ...
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Does inertia imply that a cyclindrical mass in frictionless motion on a horizontal plane keeps moving forever ( with $\vec F = O$)?
Suppose I have a perfectly cylindrical pencil and set it in motion on a perfectly smooth and horizontal table, in such a way that the axis of the pencil is in translation.
Is the state of this object ,...
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Decrease of the rotation speed of a wheel with inertia, when we stop applying rotational force to it [closed]
Let's say we have a wheel rotating at a constant speed $s$.
Suddenly at time $t=1$ we stop applying force to it.
What is the law for the decrease of the speed, until it stops?
I guess it will look ...
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Forces on us on a rotating Earth
So the earth is constantly rotating but it doesn't need a force to rotate. It'll rotate indefinitely.(?) But we and other masses on earth need a force on us to continue rotating along with earth? And ...
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Why does rotational inertia represent the resistance of a body to angular acceleration
I understand how rotational inertia, $I=mr^2$, is defined based on $\tau_z=mr^2 \alpha_z$ as an analogy to the linear inertia $m$. But I'm still not sure why it represents the resistance of a body to ...
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What would happen if an astronaut tried to swing a baseball bat in free fall?
I am interested in finding out how swinging a baseball bat or similar object would affect the astronaut's rotation in free fall, on the ISS for instance. How much would the astronaut swing the bat, ...
4
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What physical phenomenon causes racing bike to lift automatically after it fall down?
What physical phenomenon causes racing bike to lift automatically after it fall down? What causes it to travel further distance after it fall down? Please help me.
Animation:
YouTube link :https://...
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What causes a rotating object to rotate forever without external force—inertia, or something else?
Someone told me that it is not inertia, but I think it is inertia, because it will rotate forever. In my understanding, inertia is the constant motion of an object without external force. Am I wrong?
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