Suppose the sun is 1.68248 × 108 km from earth. the speed of light is 2.99792 × 108 m/s. how long does it take for its light to reach us? answer in units of min.

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.