Acceleration is zero because it is travelling at a constant speed.
Answer:
a. A
Explanation:
Kepler's First Law says that the orbits of planets are ellipses with the sun at one focus of the ellipse. Moreover, Kepler’s Second Law says that the line joining the planet to the sun sweeps out equal areas in equal times as it moves along its orbit. Finally, Kepler’s Third Law says that the ratio of the squares of the periods for two planets is equal to the ratio of the cubes of their semi-major axes.
By these laws, the comet A will have lower orbital speed.
External force.
Air resistance, friction, grass rubbing on a rolling ball, etc.
If there is no external force on a moving object, it keeps going.
Forever !
Answer:
50% of it .
Explanation:
50% of it is illuminated by the Sun.
