In: Physics
Halley’s comet has a mass of 3 x 10 14 kg, and when at its closest approach to the sun (8.79 x 10 7 km) is moving at a speed of 55 km/s. What then will be the comet's speed when it is passing Earth’s orbit?
Potential energy of the comet when it is closest to sun
Where Ms is the mass of the Sun(1.989 × 1031 kg)
mc = 3 × 1014 kg , R = 8.79 × 1010 m
Initial Kinetic energy of the comet,
Potential energy of the comet when it is passing the orbit of earth
Where RE is the distance of the earth from the sun equal to 1.496 × 1011 m.
Final kinetic energy of the comet
By law of Conservation of energy,
Therefore, comet's speed when it is in earth's orbit,