De Vico Comet orbits the Sun every 74.0 years and has an orbital eccentricity of 0.96. Find the comet's average distance from the Sun (semimajor axis). Express your answer in astronomical units to three significant figures.

Answer: The comet's average distance from the sun is 17.6AU

Explanation:

From Kepler's 3rd Law, P^2=a^3

Where P is period in years

and a is length of semi-major axis or the average distance of the comet to the sun.

Given the orbital period to be 74 years

74^2 = a^3

5476 = a^3

Cube root of 5476 = a

17.626 = a

Approximately a = 17.6 AU