Question

A big pendulum goes back and forth

once every 18.9 s. What is the
length of the pendulum?
(Unit = m)

Answer 1

T = 2π√(L/g)

For earth , g ~ 10

18.9 = 2×3.14 √(L/g)

9 = L/g

L = 90 metres

Answer 2

88m

Step-by-step explanation:

T=2π*
`√(L/g)`-->Τ/2π=
`√(L/g)`-->18.9/2π=
`√(L/g)`-->3=
`√(L/g)`-->3^2=L/g-->9=L/9.8

so L=9*9.8-->L≈88m