Question Statement
A pendulum of mass $m$ and length $l$ hangs from a cart of mass $M$ free to move horizontally. For small oscillations, the frequency is:
(A)
\sqrt{\frac{g}{l} \frac{M + m}{M}}
(B)
\sqrt{\frac{g}{l}}
(C)
\sqrt{\frac{g}{l} \frac{M}{M + m}}
(D)
\sqrt{\frac{g}{l} \frac{m}{M}}