Thirty years ago, police would check a highway for speeders by sending a helicopter up in the air and observing the time it would take for a car was observed to take 7.2 seconds to travel this distance. how much time did it take the car to travel the distance in hours?

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.