4.1 Gravitational Force Near Earth Flashcards
free fall
the motion of a falling object where the only force acting on the object is gravity
The force of air resistance acting on an object depends on many factors like…
One factor is the cross-sectional area of the object. -larger cross-sectional areas experience more air
resistance than smaller cross-sectional areas
Factor that affects the force of air resistance is the speed of the object.
-faster-moving objects experience more air
resistance
-air resistance acts opposite to the direction of
motion of the object if there is no wind.
terminal speed
the maximum constant speed of a falling object
force field
a region of space surrounding an object that can exert a force on other objects that are placed within that region and are able to interact with that force
gravitational field strength
the force per unit mass acting on an object when placed in a gravitational field
-vector quantity because it has a direction
-at Earth’s surface, the gravitational field strength is
9.8 N/kg [down].
gravitational field strength at a location has the same _____ as the ________ due to gravity at that location.
magnitude; acceleration
To determine the gravitational field strength at a particular location, you can …
measure the force of gravity acting on an object using a spring scale or force sensor and divide by the mass of the object
Careful measurements of Earth’s gravitational field strength show that its magnitude _____ as an object is moved farther away from Earth’s surface.
If the distance is large enough, Earth’s gravitational field strength becomes very _____.
decreases; weak
Since Earth is not a perfect sphere, the magnitude of the gravitational field strength at Earth’s surface, varies according to …
the geographic location of the object
the magnitude of the gravitational field strength is slightly ______ at the poles than at the equator.
greater
The magnitude of the gravitational field strength gradually increases with ________ as you travel from the equator toward either pole.
latitude
the gravitational field strength on Earth’s surface is …
9.8 N/kg [down]
mass
quantity of matter in an object
-the only way to change the mass of an object is to either …
add or remove matter
-the mass of an object does not change due to
location or changes in gravitational field strength.
Weight
a measure of the force of gravity acting on an object
Since weight and the force of gravity are the same ________, the weight of an object depends on
________ and the _________ of Earth’s gravitational field strength at that location.
quantity; location; magnitude
true or false
weight is a vector
true
when measuring weight with a force sensor or a spring scale, the object must either be ______________________ while being supported by the scale or sensor.
at rest or moving at a constant velocity
On the Moon or a planet other than Earth, your weight is ________ but your mass is the ________.
different; same
gravitational field strength
force per unit mass acting on an object placed in a gravitational field
The gravitational field strength at Earth’s surface __________ with distance from the surface of
Earth. It is ___________ at the poles and _______ at the equator because Earth is not a perfect sphere.
decreases; greater; less
