Solving for Mercury's Perihelion Distance

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AI Thread Summary
To solve for Mercury's perihelion distance, the discussion emphasizes the relationship between potential energy (Pe) and kinetic energy (Ke), noting that their sum remains constant. The problem states Mercury's orbital speeds at aphelion and perihelion, along with its distance from the sun at aphelion. The relevant equations include the gravitational potential energy formula and the concept of areal velocity from Kepler's Law, which maintains a constant value during the orbit. The participants seek clarification on the formula for areal velocity to aid in their calculations. Understanding these principles is crucial for determining Mercury's distance from the sun at perihelion.
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I have been struggling with this particular problem related to gravity.

Homework Statement


Mercury's orbital speed varies from 38.8 km/s at aphelion to 59.0 km/s at perihelion. If the planet is 6.99x10^10m from the sun's center at aphelion, how far is it at perihelion.


Homework Equations



Pe+Ke=constant

Pe= (-Gm1m2)/r2


Sun mass = 1.99x1030kg
Sun Mean Radius= 696x10m
Sun surface gravity=274m/s2
Sun Mean distance from central body=2.6x1017km

Mercury mass = .330x1024kg
Mercury mean Radius = 2.44x106m
Mercury Surface Gravity = 3.7m/s2
Mercury Mean dist. from central body = 57.6x106km
 
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According to Kepler's Law, when a planet is orbiting around the sun its areal velocity remains constant. So what is the formula for the areal velocity?
 
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