Question

A pendulum clock that keeps correct time on the earth is taken to the moon. It will run

(a) at correct rate 

(b) 6 times faster

(c) √6 times faster 

(d) √6 times slower.

Answer 1

(d) √6 times slower.

EXPLANATION:  

The time period of the pendulum of the clock on the earth T =2π√(l/g). On the moon g'=g/6. The time period on the moon T' =2π√6l/g) =√6*2π√(l/g) =√6T.  

So the pendulum will take √6 times more time in one oscillation on the moon and it will run √6 times slower. The option (d) is true.