A piece of brass of density 8.5g/cm³ has mass of 170g. A piece of wood has mass of 75g. The wood is attached to the brass and together when totally immersed in the water have mass of 125g

The period of a pendulum varies directly as the square root of the length of the pendulum and inversely as the square root of the acceleration due to gravity. find the period when the length is 144 cm and the acceleration due to gravity is 980 cm per second squared, if the period is 7pi seconds when the length is 289 cm and the acceleration due to gravity is 980 cm per second squared.