Page 477 - Canadian BC Science 9

Developing Skills
40. The figure below shows a solar system many light-years from ours. Astronomers have classified the five planets as shown and determined their distances from the star they orbit. Astronomers believe there is a sixth planet in the solar system located somewhere in the region marked X.
(a) What type of planet would you expect to find in this region?
(b) Explain your answer to (a).
(c) At what distance would you expect the
new planet to be found?
(d) Why did you choose this distance?
(e) How is this solar system arrangement
different from ours?
41. On Earth, if you drop something it falls to
the ground. The rate at which it falls is called the acceleration due to gravity. If you were to drop something while standing on another object in space, the rate of acceleration due to gravity would be different. The table in the next column shows what the mass of a 70 kg person would be if he or she stood on a variety of different objects in space. You can calculate how gravity on Earth compares with gravity on the different objects. The example of Jupiter is provided for you.
Example: How much greater is the gravity on Jupiter than on Earth?
Assume that Earth’s gravity 􏰀 1 mass of person on object
mass of person on Earth 􏰀 gravity on object compared with
837 kg gravity on Earth 70 kg 􏰀 2.5
(a) Copy the table below into your notebook and calculate the gravity relative to Earth for the asteroid, Moon, Sun, and a neutron star.
Object
Earth Jupiter asteroid Moon
Sun
neutron star
Mass on Object (kg)
19 000 000.00
Gravity Relative to Earth
1.0 2.5
1 000 800 600 400 200 0
gas giants
Planet type
rocky planets
70.00
837.00
0.05
12.00
1 913.00
(b) Explain what factors determine whether the gravity of an object in space will be more or less than the gravity on Earth.
Pause and Reflect
In this unit, you have learned about the commercialization of space travel. To date, there have only been a few space tourists willing to pay tens of millions of dollars each for a travel opportunity that is usually only for astronauts. Should space travel be available to only astronauts and the rich, or should it be accessible to the general public?
Unit 4 Review • MHR 459
Distance from star (millions of kilometres)