I'm studying the chapter Energy on Kleppner's book.

There we have an example of a Conical Pendulum.

It is said that it moves with constant angular velocity $\omega$ in a circle of constant radius $R$. Then they say that the kinetic energy $K = \frac 1 2 M R \omega^2$.

But, since $v = \omega R$, shouldn't it be $K = \frac 1 2 M R^2 \omega^2$?

  • 3
    $\begingroup$ It could be a typo, because the units are not correct in the first expression. $\endgroup$
    – tmwilson26
    Nov 18 '15 at 16:08
  • $\begingroup$ Yes you are correct, the first one has wrong dimensions on either side of the equation. $\endgroup$ Nov 18 '15 at 16:13
  • $\begingroup$ yes, the expression you wrote is correct (not the one in the book) $\endgroup$
    – user83548
    Nov 18 '15 at 17:34
  • $\begingroup$ It must be that the book should have $K = \frac 1 2 M (R \omega)^2$ but they forgot to typeset the parenthesis, $\endgroup$ Dec 30 '18 at 22:13

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