Inverse Square Relationship
1. The force of gravity on an astronaut is 600 N at the Earth’s surface. What is the force of gravity
on him at each of the following distances from the center of the Earth, measured in MULTIPLES
of the Earth’s radius?
a. 2
b. 5
c. 10
d. 20
2. The force of gravity on a spacecraft some distance from the Earth is 800 N. What would that
force be if its distance to the Earth’s center were:
a. One-half as great?
b. One-third as great?
c. One-tenth as great?
d. One-quarter as great?
On the following problems, you will use the inverse square relationship to help quickly find out the
desired values.
3. Suppose that two objects attract each other with a gravitational force of 20 N. If the distance
between the two objects is halved, what is the new force of attraction between the two
objects?
4. Suppose that two objects attract each other with a gravitational force of 20 N. If the distance
between the two objects is doubled, then what is the new force of attraction between the two
objects?
5. Suppose that two objects attract each other with a gravitational force of 20 N. If the mass of
both objects was halved, and if the distance between the objects remained the same, then what
would be the new force of attraction between the two objects?
6. Suppose that two objects attract each other with a gravitational force of 20 N. If the mass of
both objects was doubled, and if the distance between the objects was doubled, then what
would be the new force of attraction between the two objects?
7. Suppose that two objects attract each other with a gravitational force. If the mass of both
objects was reduced by one-third, and if the distance between the objects was halved, then
what would be the new force of attraction between the two objects?
8. Suppose that two objects attract each other with a gravitational force. If the mass of object 1
was tripled, and if the distance between the objects was quadrupled, then what would be the
new force of attraction between the two objects?