Question

1. Could you find the Mass of the Sun using the slope of the of T² versus a³, using the values that are in units of years and AU? Explain.

2. Suppose we discovered a planetary body orbiting our Sun at a distance of 15 AU. How long would this world take to complete one orbit around the Sun? (show your work)

3. Suppose Astronomers noticed a moon around the newly discovered planet in Question 2. By watching this moon, noting its period and distance from the planet, which of the following could they find: the mass of the moon, the mass of the planet, both masses, neither mass. Explain.

Answer 1

Suppose we discovered a planetary body orbiting our Sun at a distance of 15 AU. How long would this world take to complete one orbit around the Sun

just use Kepler's third law

T² = r³

for this to work, the time period (T) is in Earth years and distance from sun (r) is in AU

so,

T² = 15³

T = 59.1 earth years

_______________________

Suppose Astronomers noticed a moon around the newly discovered planet in Question 2. By watching this moon, noting its period and distance from the planet, which of the following could they find: the mass of the moon, the mass of the planet, both masses, neither mass. Explain.

the thing we know

the period of the moon around the planet and distance of the moon from planet.

with this info, we can only find mass of the planet.