A disc in space will rotate or not?

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mooncrater
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Homework Statement


Consider this question:
"A uniform thin flat isolated disc is floating in space. It has radius R and mass m. A force F is applied to it at a distance ##d=\frac {R}{2}## from the centre of the disc. So,
Will the disc rotate with accelerating in the direction of force or it won't rotate and will accelerate only?

Homework Equations

The Attempt at a Solution


I think it won't rotate. If it will then it's not clear which point is chosen as the centre of rotation. If it is the centre of the disc, then why is it chosen? I am confused about this thing.
 
mooncrater said:

Homework Statement


Consider this question:
"A uniform thin flat isolated disc is floating in space. It has radius R and mass m. A force F is applied to it at a distance ##d=\frac {R}{2}## from the centre of the disc. So,
Will the disc rotate with accelerating in the direction of force or it won't rotate and will accelerate only?

Homework Equations

The Attempt at a Solution


I think it won't rotate. If it will then it's not clear which point is chosen as the centre of rotation. If it is the centre of the disc, then why is it chosen? I am confused about this thing.

Suppose a disc is rotating about a point on its edge. What can you say about the motion of its centre of mass?
 
Handwritten physics diagram split by a vertical line into two parts. Left: a circle with a centre dot and an upward force F applied at its top edge, with equations F = m a_cm, F R/2 = I_cm alpha. Right: a circle with a centre dot and a leftward force F applied at its left edge, with equations F = m a_cm and alpha = 0.
 
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