I didnt know under what category to post this so here goes...
I have formulas but confusd which to use when. pls help. Maybe u can direct which formula to use and i will proceed from there.

Uranus orbits the Sun with an orbital radius of 2.56 x 107 m. Given that the mass of the Sun 1.99 x 1030 kg, calculate the period of Uranus’s orbit in seconds.



Venus orbits the Sun with an orbital radius of 6.05 x 106 m. Given that the mass of the Sun is 1.99 x 1030 kg, calculate the orbital velocity of Venus



Calculate the force of gravitational attraction between two spheres of mass 50.0 kg and 75.0 kg that are 20.8 m apart

A satellite orbits Pluto 1.20 x 105 m above its surface. Given that the mass of Pluto is 1.25 x 1022 kg and the radius of Pluto is 1.20 x 108 m, calculate the period of orbit of the satellite in seconds.


The Moon has an orbital period of 27.3 days around Earth and a mean distance of 3.84 ´ 105 km from Earth’s center. Use Kepler’s laws to find the orbital period of an artificial satellite orbiting Earth at a distance of 2.55 x104 km from the center of Earth

The distance between Pluto and the Sun is 57.2 times more than the distance between the Sun and Earth. Calculate the time taken by Pluto to orbit the Sun in Earth days.

Find the magnitude of the force required to accelerate an electron of mass 5.30 x 10 -3 kg from rest to a speed of 0.8 x 1010 m/s for a distance of 2.50 cm?