How Long Does It Take a Comet to Travel 80 Degrees Around the Sun?

[Mastablade]

Homework Statement

A comet passes the sun at a distance of closest approach R = 6 * 10^8 m and speed 8 * 10^5 m/sec. How long will it take to travel 80 degrees around its orbit from the point of closest approach.

Homework Equations

omega = velocity / radius

The Attempt at a Solution

Since we can get omega from the above information, I should only have to integrate omega and set that equal to 80 degrees (or 4/9 pi radians)
omega = 8 * 10^5 / (6 * 10^8) or 1/750
the integral of this makes 1/750t and set that equal to 4/9 pi radians so,

t = (750 * 4 * pi)/9
t = 1047.2 seconds

I am not sure if this is the proper way of writing this equation and confirmation would be appreciated. Thanks in advance.

 

[tiny-tim]

Hi Mastablade!

(have an omega: ω and a pi: π )

No, that's for a circular orbit.

A comet goes round the sun in a very elongated ellipse.