'The earth moves round the Sun on a circular orbit of radius 1.5x10^11 m, taking 365.25 days for each orbit. Calculate:
a) the speed
b) the centripetal acceleration of the earth on its orbit around the sun.
Part B
A satellite is in orbit just above the surface of a spherical planet which has the same radius as the earth and the same acceleration of freefall at its surface. Calculate:
a) the speed
b) the time taken for 1 complete orbit of this satellite.
Radius of the earth = 6400km, Acceleration of free fall = 9.8 ms^-2'
I've done part A and got v = 3.0x10^4 ms^-1 and a = 5.9x10^-3 ms^-2 but I can't figure out which equation to use to do the next part with the information given. Can anyone point me in the right direction? Thanks