Well first of all, a planet doesn't have a semimajor axis, although it's orbit does.
In an orbit with a smaller semimajor axis, the planet moves faster, and its orbital period is shorter.
That's why the International Space Station circles the Earth in less time than the Moon does.
1.Landslide 2. Delta 3. Moving water 4. Erosion 5. Abrasion and Deflation
6. Winds 8. Sediment it can erode
Sorry, don't know 7.
A flat line means the the speed is the same . Its moving at the same pace.
Yes it can because it had lots of force
