1. A planetoid has an average distance of 3.6 X 1013 m from the sun. What is its orbital
period? (3 marks)
2. Suppose a tenth planet was discovered which has an orbit with a period that is 1.8 times that
of Pluto. What would be the radius of its orbit? The period of Pluto is 7.82 X 109 s.
(3 marks)
3. The mass of object one is M and object two is M1. The force of gravitational attraction
between them is 138 N. Two different objects, one with mass 3M and the other with mass
2M1 are twice as far apart as the first two objects. What is the gravitational attraction between
the second pair of objects? (3 marks)
4. A man's weight on earth is 650 N. If a planet has a radius of 0.89 times earth's radius, and a
mass of 0.38 times earth's mass, what is the weight of the man on this other planet? (4 marks)
5. A planet has a mass of 1.7 X 1023 kg and a radius of 6.34 X 105 m. What is the acceleration
due to gravity on the planet? (3 marks)
6. A moon of a planet has a period of 3.7 X 104 s. The radius of the orbit is 5.33 X 107 m.
What is the mass of the planet? (3 marks)
7. What is the distance above Jupiter a satellite must be placed in order to have a synchronous
orbit? The mass, rotational period, and radius of Jupiter are 1.90 X 1027 kg, 9.833 h and
7.18 X 107 m respectively. (3 marks)
8. A colony on the moon wants to put a satellite into a synchronous orbit. What velocity is
needed to place the satellite in orbit, and how high above the surface of the moon is the
satellite? The moon has mass of 7.34 X 1022 kg, period of rotation of 2.36 X 106 s, and
radius of 1.74 X 106 m. (5 marks)
November 22, 2013