We r made of atom so v can’t touch anything hehe I just joking
The buoyant force exerted by a liquid is equal to the weight of the fluid <span>displaced.</span>
T = 2*pi*Sqrt (L/g)
T = Period = Time to complete one oscillation, L = Length of the pendulum, g = gravitational acceleration.
Then,
L = {T/(2*pi)}^2*g = {7/(2*pi)}^2*3.711 = 4.606 m