Question

A meteorite of mass 1*10^4kg is approaching head-on a planet of mass 5*10^29kg and radius 5*10^4km. Assume that the meteorite is initially at a very large distance from the planet where it has a speed 3*10^2km/s. Take 6.67*10^-11.

Determine the speed of the meteorite (in m/s) just before it hits the surface of the planet. (The planet has no atmosphere, so we can neglect all friction before impact)

v=

Answer 1

34534563456

Answer 2

please tell the formuka

Answer 3

I know its the initial KE+initial PE=final KE... but how do we calculate the initial PE? GMm/R.... but what R do we sue ehre? Its beens tated that the meteorite is already really far away from the planet initially..???

Answer 4

Given that its really far away from the planet you can assume that PE = 0