The frequency of a simple pendulum with length is to be doubled

PHYSICS · Single correct · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics

Problem

The frequency of a simple pendulum with length

L_1 = 1.0\,\text{m}

is to be doubled. Which of the following is the closest new length

L_2

required to achieve this change at the same place? (a)

0.50\,\text{m}

(b)

0.125\,\text{m}

(c)

0.25\,\text{m}

(d)

2.0\,\text{m}