Gravity Concept Inventory
Please answer the following questions about Newtonian gravity to the best of your ability. This questionnaire is for research purposes only, so your performance will NOT affect your grade in any way, and your participation is optional. Your student ID number will be used for matching your responses to other data, but your information will be destroyed after the study is over.
SELECT THE SINGLE “BEST” CHOICE
1. Besides gravity, what other factors, if any, hold us to the Earth’s surface?
a. Air pressure from the Earth’s atmosphere.
b. Forces from the Earth’s spinning motion.
c. Magnetism from the Earth’s magnetic field.
d. No other factors; gravity is the only one.
2. How would the gravitational force between the Earth and Moon differ if the Moon were twice as far
as it is now?
a. Would be the same.
b. Would decrease by less than two times.
c. Would decrease by exactly two times.
d. Would decrease by more than two times.
e. Would increase.
3. Two astronauts are floating in space far away from any planets or stars. What is the direction of the
gravitational force that they experience, if any?
a. Toward each other, because there is a gravitational force between them.
b. Away from each other because they are pulled by distant planets and stars.
c. They experience a gravitational force, but its direction cannot be determined.
d. They do not experience a gravitational force because there is no large object nearby.
4. Astronauts appear weightless in their Earth-orbiting spacecraft because…
a. They have escaped Earth’s gravity.
b. There is no air in the spacecraft.
c. They are moving at the same rate as their spacecraft.
d. The spacecraft’s rocket engines counteract gravity.
i5. The factor(s) that most affect the gravitational force between two objects are:
a. size and distance
b. mass and size
c. density and distance
d. mass and distance
e. density and size
6. Planets A, B and C are identical. A and C have a giant moon orbiting them, while B has a
lightweight artificial satellite orbiting it, as shown in the diagram. Which planet has the strongest
gravitational interaction with its satellite?
a. Planet A, because its moon is heavy and close to it.
b. Planet B, because only a lightweight object can orbit without falling down.
c. Planet C, because it can interact with a heavy object that is far away.
d. All have the same gravitational attraction, because the planets are all the same mass.
e. Not enough information to determine.
7. Why doesn’t the gravitational pull between the Sun and the planets cause the planets to fall into the
a. The background stars pull back on the planets.
b. The Sun’s magnetic fields are pushing out.
c. The speed of the planets flings them out.
d. The Sun’s rotation pushes the planets out.
8. Satellites B is three times more massive than A, but orbiting the planet at three times the distance.
Compare the force of gravity between each satellite and the planet. The diagram is not to scale.
a. A experiences a stronger force than B, because
differences in distance are more influential than
differences in mass.
b. B experiences a stronger force than A, because
differences in mass are more influential than
differences in distance.
c. A and B experience the same force, because differences
in distance are exactly compensated
by differences in mass.
d. A and B experience no force, because they are in space.
9. Assuming the Earth is perfectly round and each person is the same
mass, which person standing on Earth’s surface experiences a
stronger force of gravity?
a. Both A and