find the acceleration of gravity for a pendulum that oscillates 1.5 times every 18 seconds and has a length of 3.54m

Fundamental equation for SHM:   w = (k/m)^1/2  where w is angular frequency

Or since P = 1 / f = 2 pi / w = 2 pi (m / k)^1/2

The equivalent equation for a simple pendulum is:

P = 2 pi (L / g)^1/2    or g = 4 pi^2 L / P^2

g = 4 pi^2 * 3.54 / 12^2 = .971 m / s^2

Something wrong - should be 9.71 m / s^2

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day