Answer
(a) $1.2s$
(b) $0.91\frac{m}{s}$
Work Step by Step
(a) We know that
$T=2\pi \sqrt{\frac{2L}{3g}}$
We plug in the known values to obtain:
$T=2\pi\sqrt{\frac{2(0.55)}{3(9.81)}}$
$T=1.2s$
(b) The required speed can be determined as
$v=\frac{d}{\frac{1}{2}T}$
We plug in the known values to obtain:
$v=\frac{0.55}{0.607}=0.91\frac{m}{s}$
