Comet on a parabolic orbit around the Sun

[math 2015]

Homework Statement

given: the speed at perihelion

What is comets full energy? What is its distance from Sun at perihelion?
How much time is the comet located inside Earth's orbit?

Homework Equations

parabolic orbit equation

3. The attempt at a solutin
wrongly calculated l

 

[theodoros.mihos]

$$ r(\theta) = \frac{L^2}{GMm^3}\,\frac{1}{1+\epsilon\,\cos{\theta}} $$
L is constant, so the same for every $\theta$. Take an easy value.

 

[gneill]

Homework Statement

given: the speed at perihelion

What is comets full energy? What is its distance from Sun at perihelion?
How much time is the comet located inside Earth's orbit?

You're first asked about the "full energy" of the of the comet's orbit. Presumably that's the mechanical energy. What is the expression for the specific mechanical energy (ξ) of an orbit? What is its value for any parabolic orbit?

In order to answer the part about the time spent within the Earth's orbit you will need some hard data. Are you given an actual value for the speed at perihelion?

 

[math 2015]

94 km/s

 

[gneill]

94 km/s

Okay, now you'll have to show some details of your efforts so far to answer the given problem.

 

[gneill]

@math 2015 I'm closing this thread since you haven't shown any effort. If you wish to continue, contact me or begin a new thread showing your attempt in detail.