Physics Gravitation Level: High School

(a) The small spherical planet called “Glob” has a mass of 7.58E + 18 kg and a radius of 6.26E + 4m . An astronaut on the surface of Glob throws a rock straight up . The rock reaches a maximum height of 2.44E + 3 m , above the surface of the planet , before it falls back down . What was the initial speed of the rock as it left the astronaut’s hand ? (Glob has no atmosphere, so no energy is lost to air friction . G = 6.67E-11 Nm^2/kg^2.)

(b) A 25.0 kg satellite is in a circular orbit with a radius of 1.55E + 5 m around the planet Glob . Calculate the speed of the satellite .