Answer
a. 1.4 s
b. Undefined
Work Step by Step
a. The period of a pendulum is given by $T=2 \pi \sqrt{\frac{\mathcal{l}}{g}}$. Use the given length and solve for the period of 1.4 s.
b. In the freefalling elevator, the mass will not swing back to equilibrium, so the period is infinite (or undefined).