Noncontact Forces 8th Grade Assessment

Which of the following describes gravitational force?

• contact, attractive

• contact, repulsive

• noncontact, repulsive

• noncontact, attractive

Which of the following describes the cause and effect relationship between gravity and falling objects?

• An object’s force is caused by gravity’s attraction to the center of Earth.

• Gravity causes objects to fall toward the center of Earth.

• Gravity causes objects to repel from the center of Earth.

• Gravity is caused by objects’ attraction to the center of Earth.

Which object has greater acceleration when acted on by gravitational forces? A 2 kg apple, a 7 kg bowling ball, or a 20 kg rock?

• the 2 kg apple

• the 7 kg bowling ball

• the 20 kg rock

• They all have the same acceleration when acted on by gravitational forces.

Why doesn’t a feather fall at the same rate as an apple?

• Air resistance increases an object’s downward acceleration and affects objects differently.

• Air resistance reduces an object’s downward acceleration and affects objects differently.

• Gravitational forces affect different objects in different ways.

• Feathers are too light to be affected by gravitational forces.

Why is the moon never pulled into the Earth despite gravitational forces that pull it toward Earth?

• The moon moves forward fast enough so that it is never pulled into Earth.

• The moon is so large that gravity repels it from Earth rather than pulls it.

• The moon is pulled toward the sun with a force equal to Earth’s pull on it.

• The moon has enough of its own gravity to avoid being pulled to Earth.

Why do gravitational forces form structures in space?

• Stars and planets have very small masses, so gravitational forces work over large distances.

• Stars and planets have very large masses, so gravitational forces work over large distances.

• Stars and planets have very small masses, so gravitational forces work over very short distances.

• Stars and planets have very large masses, so gravitational forces work over very short distances.

Why do astronauts in a space station in orbit not hit the floor of the space station?

• There is no gravitational force working on the astronauts.

• The astronauts and the space station fall to Earth at the same rate.

• The astronauts’ masses are too small to be affected by the pull of Earth’s gravity.

• The astronauts are protected from the pull of gravitational forces by the space station.

What two factors determine the strength of the gravitational force between two objects?

• acceleration and distance

• speed and distance

• mass and distance

• mass and speed

Which of the following is true of the strength of gravitational forces between two objects in relation to mass?

• Gravitational forces are greater when objects have a large mass.

• Gravitational forces are the same regardless of the mass of the objects.

• Gravitational forces are greater when objects have a small mass.

• Gravitational forces are weaker when objects have a large mass.

The strength of a gravitational field ______ with an increase in distance.

• stays the same

• varies

• decreases

• increases