question_answer

A uniform rod or mass m and length l is held \[{{60}^{\text{o}}}\] with the vertical. . What will be the potential this position?

A)  Zero                                     

B)  \[\frac{mgl}{4}\]

C)  \[\frac{mgl}{2}\]                             

D)         \[mgl\]

Correct Answer: C

Solution :

Vertical height \[=h=l\cos {{60}^{o}}\] and   potential energy \[=mgh\]                 \[=mgl\cos {{60}^{o}}\]                 \[=\frac{mgl}{2}\]