Question

Big Ben’s pendulum takes 4 s to swing back and forth. The formula   gives the swing time, t, in seconds, based on the length of the pendulum, L, in feet. What is the minimum length necessary to build a clock with a pendulum that takes longer than Big Ben’s pendulum to swing back and forth?

1. 32 feet
2. 41 feet
3. 40 feet
4. 56 feet