Pls help I'm stuck

Slow all of your work 1. What is the mass of a planet if when it is a distance of 2.90 x 1012 m from the center of the sun the force of attraction is 1.38 x 1021 N? (2 marks) 2. A 8.00 x 103 kg satellite is orbiting 625 km above the earth. (4 marks) a. Determine the acceleration due to gravity experienced by the satellite b. Determine the distance above the earth that a satellite of the same mass will orbit if it experiences only half the acceleration of the satellite in part a. 3. A silver Nissan 370Z Roadster with a mass of 1375 kg has a speed of 30.0 m/s when it travels through a 90.0 corner (quarter of a circle) with a radius of 45.0 m. (6 marks) a. How long does it take the Roadster to negotiate the curve? b. What is the centripetal acceleration of the Roadster? c. What is the minimum friction force required for the Roadster to negotiate the curve without skidding