posted by Larry on .
The period of revolution of a planet around the sun is the time it takes for the planet to complete one orbit of the sun. The period, P years, is give by Kepler's third law P^2=D^3, where D is the average distance from the sun in astronomical units (AU). One AU is the average distance f the Earth fromt he sun. Use the average distance formt he sun to find the period of revolution for Jupiter; 5.20 AU to the nearest tenth of a year.
I don't get that, the teacher said the answer was 11.9 I think. Anyone care to explain how?
5.20 AU is the distance so:
P^2=D^3 is equivalent to:
5.20^3 is 140.608, 140.608 is the period.
So the new equation would be:
Since you now know that 140.608 is the period squared, the opposite of squaring is square rooting. So this is how you would write it.
It asked for the nearest tenth of the year so rounding up would make the answer 11.9
So the period of revolution for Jupiter is 11.9 years.