The length of a pendulum varies directly with the square of the period of the pendulum. If a pendulum 2m long has a period of 4 seconds (s), what is the length of a pendulum with a period of 10s?
a. 1.25m
b. 12.5m
c. 80m
d. 800m
a. 1.25m
b. 12.5m
c. 80m
d. 800m