How to Calculate Comet Halley's Distance from the Sun Using Kepler's Laws

[bcd201115]

Homework Statement

Comet Halley approaches the Sun to within 0.570 AU, and its orbital period is 75.6 yr. (AU is the symbol for astronomical unit, where 1 AU = 1.50 x 10¹¹ m is the mean Earth-Sun distance.) How far from the Sun will Halley's comet travel before it starts its return journey.

Homework Equations

Can anyone help me with this?

The Attempt at a Solution

I've already figured that .57 AU = 8550 m

 

[gneill]

Homework Statement

Comet Halley approaches the Sun to within 0.570 AU, and its orbital period is 75.6 yr. (AU is the symbol for astronomical unit, where 1 AU = 1.50 x 10¹¹ m is the mean Earth-Sun distance.) How far from the Sun will Halley's comet travel before it starts its return journey.

Homework Equations

Can anyone help me with this?

The Attempt at a Solution

I've already figured that .57 AU = 8550 m

Your value for r_p, the perihelion distance, looks a tad small. Did you lose a few orders of magnitude somewhere?

If you choose an appropriate unit system you shouldn't have to do any conversions

Which of Kepler's laws do you think might be applicable here, given the values that you know.