# A projectile is ejected with vertical speed v from the surface of a planet of mass M and radius R. [closed]

–1 vote
18 views

Show that it comes to rest at a distance r from the centre of the planet where $$r=R/(1−Rv^2/2GM)$$
If v = c in the above example what will be the condition between M and R such that the planet acts like a Newtonian black hole.