Help with these four questions please

5. If the gravitational force between a planet of mass M and a satellite of mass m at distance r is 2.5 x 10' N, what is the force exerted on a larger satellite of mass 2m, at a distance 0.8r away from planet M? AN 5) 2 marks 6. Three balls are placed as shown. 4.5 kg 3.0 kg Y 1.6 kg What is the magnitude and direction of the gravitational force 2.4 m 1.2 m exerted on mass Y by mass X and mass Z? 7. Saturn's moon Enceladus has a mass of 1.08 x 1020 kg and a radius of 2.52 x 105 m. What speed would be required for a 75.0 kg satellite to be in a stable orbit 165 km above the surface of this moon? 7 ) 4 marks 8. A 4.0 x 10' kg satellite orbits an unknown planet once every 1.0 x 10' s in a circular orbit of radius 2.0 x 10 m. What is the mass of the planet