Download Name: Practice - 6.5 Newton`s Universal Law of Gravitation 1. Solar

Name: ___________________________
Practice - 6.5 Newton’s Universal Law of Gravitation
1. Solar System Forces
Mass
Sun
1.99 x 1030 kg
Earth
5.97 x 1024 kg
Moon
7.35 x 1022 kg
G = 6.67 x 10-11 N m2/kg2
1 AU = 1.50 x 108 km
A. Calculate the gravitational force between the Sun and the Earth.
B. The average distance between the Earth and Moon is 3.84 x 105 km. Calculate
the gravitational force between these two bodies.
C. Something to Think About: If the force between the Sun and Earth is greater
than the force between the Earth and the Moon, then why does the Moon have
more influence on the ocean tides?
2. The average weight of a human female is 59 kg and the average of a human male is 79
kg. Calculate the average (gravitational) attraction between a male and female one meter
apart.
3. Knowing that the centripetal force between the Sun and the Earth is gravitational
force, equate the two equations and determine the orbital speed of the Earth.
4. The weight of an object is the force of gravity pulling it down.
A. Determine the acceleration due to gravity g on the Earth’s surface. The radius
of the Earth is 6378 kilometers.
B. Determine the acceleration due to gravity g on the Moon’s surface. The radius
of the Moon is 1737 kilometers.
C. A 2.0 kg hammer was dropped by one of the Apollo astronauts on the Moon from
a height of 1.5 m. How long did it take to hit the ground?
Solutions:
1. A. 3.52 x 1022 N
B. 1.98 x 1020 N
3. 2.97 x 104 m/s (29.7 km/s)
4. A. 9.79 m/s2
2. 3.11 x 10-7 N
B. 1.62 m/s2
C. 1.36 s