[samueltaylor123]

Problem is on attatchment.
To solve, I tried to consider the path taken as a section of the circumference, but no use. I'm guessing its to do with the photon detection, but I cant work it out.

Any help?

[Xdaamno]

Two objects in the same orbit around a planet always have the same speed, right?

At the same altitude, their centripetal accelerations due to gravity are the same. Relations like v=√(ar) show that this implies their speeds are the same.

[samueltaylor123]

Right, I was wondering that, just it seems pretty simple. Its a 3 mark question, which would be quite generous

[samueltaylor123]

(Original post by Xdaamno)
Two objects in the same orbit around a planet always have the same speed, right?

At the same altitude, their centripetal accelerations due to gravity are the same. Relations like v=√(ar) show that this implies their speeds are the same.

It dosent say they have the same mass, so the centripetal force isnt neccesarily the same surely?

[XiaoXiao1]

Both the gravitational force of attraction and the required centripetal force are proportional to the mass of the orbiting object, therefore it's speed is independent of mass (in a similar way to the fact that the acceleration of free fall for all objects on earth is the same when you neglect air resistance).

[samueltaylor123]

oh yeah of course, cheers