How Can I Measure Kinetic Energy in a Non-Inertial Reference Frame?

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To measure kinetic energy in a non-inertial reference frame, the formula K = (Moment of Inertia about an axis through A * Angular Velocity^2)/2 + (Mass * Velocity^2)/2 is proposed, yielding K = 9.5. However, there is ambiguity regarding the reference frame's rotation and the interpretation of "with respect to point A." It is suggested that if the moment of inertia is calculated about the axis of rotation, the linear kinetic energy term may lead to double counting. Observers in the non-inertial frame must consider the rigid body's instantaneous motion as a combination of linear motion and rotation about its mass center. Clarifying these aspects is essential for accurate kinetic energy measurement.
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TL;DR Summary: I think A is an non inertial reference frame.So how can I measure kinetic energy about it?

I found a solution to the problem which states that Kinetic Energy about A= (Moment of Inertia about an axis passing through A*Angular Velocity^2)/2+(Mass*Velocity^2)/2 .Thus K=9.5.Can anyone please show me the derivation of this formula?
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The first difficulty is that "with respect to point A" is ambiguous.
It is reasonable to assume, as you have, that it does not mean the fixed point in space where that corner happens to be at some instant; rather, it moves with that corner of the plate. But that still does not answer whether the reference frame is also rotating with the plate. Consider both cases.
In each case, think of what an observer in the frame would see the plate as doing.
xkcda said:
Kinetic Energy about A= (Moment of Inertia about an axis passing through A*Angular Velocity^2)/2+(Mass*Velocity^2)/2
That seems very unlikely to be right. If you take the moment of inertia about the axis of rotation then you should not need to be adding a linear KE term: that would be double counting. Generally speaking, you can consider the instantaneous motion of a rigid body as the sum of the linear motion of its mass centre and its rotation about its mass centre. So if you have an ##mv^2## term for the linear component then the moment of inertia should be about the mass centre.
 
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