The intensity of sound is measured on the decibel scale, db. the equation db=10log i represents the decibel level, where i is the ratio of the sound to the human hearing threshold. a noise registers a decibel level of 29. which equation could be used to find how many times greater the noise is than the human hearing threshold.

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.