Question

More than orbital speed
if we pushed a planet with more than orbital speeds, what would happen?

Answer 1

@Vincent-Lyon.Fr

Answer 2

The planet would have an elliptical orbit.
If the planet is pushed with less than circular orbital speed, it would also be elliptical, though the focus of the ellipse would be different.

Answer 3

Ok so in either case, the planet should pass through that initial point where i pushed it right?

Answer 4

and that gives me another question.. what is the min. speed that the planet orbits?

at some point it would crash in right??
i had thought orbital velocity was the minimum velocity.. else it would crash :O :O !!!

Answer 5

Q: Ok so in either case, the planet should pass through that initial point where i pushed it right?
A: right. Gravitational orbits are closed and periodic.

Answer 6

See the 3 types of orbits according to initial velocity.

Answer 7

There is no minimal velocity if the "star" is a point-mass.

Actual minimal velocity is when radius of the planet is equal to radius of the star at perihelion.
Just add a circle simulating a non point-like Sun on my sketch.

Answer 8

so there must be some minimum velocity at every height, such that it just orbits right?

or if we consider two objects to be point masses, then they will always orbit.. but in reality to calculate that minimum speed such that they don't crash, i need to consider the size of sun and planet?

Answer 9

ahh got it.. thank you :D.. !!!

Answer 10

We gave the same answer at the same time ;-)

Answer 11

haha yea :D..