maybe w= 2pi/tCan you add some thoughts please?
Perhaps some relevant equations?
I'm afraid that is the formula for a pendulum with length L.maybe w= 2pi/t
I tried (2pi)sqrt(L/g) solve to L But I dont get the 0.022 m that is the book answer
Good!it could be get the aceleration to get the force
to try f = Kx