an empty density bottle has a mass of 25g. its mass 1550g when full of water and 45g when full of another liquid. what is the density of the liquid in kgm-3​

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.