Gravity
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.
Why do gravitational forces form structures in space?
Stars and planets have very large masses, so gravitational forces work over large distances.
An orbit is a path that
an object in space follows around another object due to gravitational forces.
The strength of a gravitational field ______ with an increase in distance.
decreases
What two factors determine the strength of the gravitational force between two objects?
mass and distance
How do you describe gravity?
noncontact, attractive
An object's mass measures
the amount of mass in an object
A force field models
the force on an object if the object were placed in any location in space.
Gravitational forces that hold objects in space are also responsible for
the motions, groupings, and shapes of those objects
The strength of gravitational forces on an object near Earth's surface depends on
the object's mass.
An object's weight measures
the strength or amount of gravity acting on an object
What is the acceleration rate caused by gravity on Earth?
9.8 m/s2
Why doesn't a feather fall at the same rate as an apple?
Air resistance reduces an object's downward acceleration and affects objects differently.
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.
Which of the following is true of the strength of gravitational forces between two objects at a distance?
Gravitational forces are stronger when objects are close and weaker when they are farther apart.
Which of the following describes the cause and effect relationship between gravity and falling objects?
Gravity causes objects to fall toward the center of Earth.
What is the cause and effect relationship between orbits and gravity?
Gravity causes the effect of moving in an orbit.
What is likely to happen to the way an object moves if gravitational forces on the object do not change?
The object will move in predictable ways
Why doesn't a space station (and the astronauts in it) float away into space?
The space station is still close enough to Earth for Earth's gravitational forces to act on it.
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?
They all have the same acceleration when acted on by gravitational forces
Why do astronauts in a space station in orbit not hit the floor of the space station?
They are falling to Earth at the same rate as the space station