if force is perpendicular to motion,then is kinetic energy constant?

Question

anonymous · Answer

yes precisely.. we say no work is being done.. only direction changes !

anonymous · Answer

Well lets look at this situation!
$$K _{E} = \frac{ 1 }{ 2} mv ^{2}$$
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anonymous · Answer

Work = $$Fd$$= $$\Delta K _{E}$$

So, since the force is constant over the displacement there is no change in Kinetic Energy.

anonymous · Answer

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As Mashy said, the only thing that is going to change is the ball's direction.
Work is being done on it to change it direction though.


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anonymous · Answer

But if you account the work done also by friction, the yes. Kinetic energy changing, In fact. Is decreasing.

anonymous · Answer

you mean kinetic energy changes

anonymous · Answer

Simple answer to your question would be like what Mashy said.
But keep in mind of friction.