Chapter 9 Conceptual Physics
which is most responsible for earths ocean tides?
moon
If the sun became twice as massive, your attraction to the sun would double and your weight as measured on earth would
not change
newton discovered
that gravity is universal
imagine you are standing atop a ladder so tall that you are 4 earth radii from earths center. wheat is your weight at the top of the ladder, relative to your weight on the ground
1/16 as much
a weight watcher who normally weighs 400 N stands on top of a very tall ladder so she is one Earth radius above earth's surface. how much is her weight there
100 N
suppose the gravitational force between two massive spheres is 80 N. If the distance between the spheres is doubled, what is the force between the masses
20 N
what is the force of gravity on a 500 N woman standing on earth's surface
500 N
a very massive object A and a less massive object B move toward each other under the influence of gravity. Which force, if either, is greater
both forces are the same
when a star collapses to form a black hole, its mass
remains the same
to make a profit, a buyer purchases metal by weight at one altitude and sells it at the same price per pound at another altitude. the supplier would
buy at high altitude and sell at a low altitude
if earth's radius somehow increased with no change in mass, your weight would
decrease
if earths mass decreased to one half its original mass with no change in radius, then your weight would
decrease to half
on each given day and location. tides rise and fall at
different times
which is greater, the gravitational force between earth and the moon, or the force between earth and the sun?
earth -- sun
During an eclipse of the sun (when the moon and the sun are totally lined up) the high ocean tides on earth are
extra high
newton has the insight to see that the
force on the moon has the same nature as the force on an apple
according to newton, the greater the mass of interacting objects, the
greater the gravitational force between them
If the mass of Earth somehow increased with no change in radius, your weight would
increase also
as two objects moving toward each other due to gravity get closer, the acceleration of each
increases
If the moon had twice as much mass and still orbits Earth at the same distance, ocean bulges on earth would be
larger
When you weigh yourself on a bathroom scale on a slight incline instead of a level surface, your weight reading on the scale will be
less
The force of gravity acting on you will increase if you
stand on a planet with a radius that is shrinking
the force of gravity acting on you will increase if you
stand on a planet with a shrinking radius
which pulls on the oceans of earth with a greater force
sun
if the sun were twice as massive
the pull of the earth on the sun would double the pull on earth would double *both of these*
a black hole is
the remains of a giant star that has undergone gravitational collapse
if the sun collapsed to a black hole, earth's gravitational attraction to it would be
the same
a planet has half the mass of the earth and half the radius. compared to its weight on earth. an apple on this planet would weigh
twice as much
tidal forces in general are the result of
unequal forces acting on different parts of a body
in comparison with other fundamental forces, the universal gravitational constant G indicates that gravity is
very weak
the earth is closer to the sun in january than in july, which accounts for the fact that the highest high tides in the northern hemisphere occur in
winter
your weight is the force
you exert against a supporting surface
if you were to weigh yourself in an elevator that is in free fall, compared to your ordinary weight, you would weigh
zero
the best time for digging clams (when the tide is extra low) is during the time of the
new or full moon
the force of gravity on you is greatest when you are standing
on earth's surface
the main reason ocean tides exist is that the moons pull is stronger
on water closer to it than on water farther away
the force of earth's gravity on a capsule in space will lessen as it moves farther away. if the capsule moves to twice its distance the force toward earth becomes
one fourth
according to newton, when the distance between two interacting objects doubles, the gravitational force is
one quarter
half-way to the center of a planet of uniform density, your weight compared to that at the surface would be
one-half
the force of gravity acts on all apples on an apple tree. some apples are twice as far from the ground as others. for the same mass these twice-as-high apples have
practically the same weight
if a block is set sliding on a huge imaginary frictionless plane in contact with Earths surface, it will NOT sustain a constant speed because
a component of gravitational force
we do not observe tides in a community swimming pool because
all parts of it are practically the same distance from the moon
the force of Earth's gravity on a capsule in space increases as ti comes closer. when the capsule moves to half its distance, the force toward earth is then
four times greater
a lunar month is about 28 days. if the moon were closer to earth than it is now, the lunar month would be
less than 28 days
if you were to weigh yourself in an elevator that is accelerating upward, compared to your ordinary weight you would weigh
more
what would a person who weights 630 N on earth weight on a planet that has the same mass as earth but half its radius
2520 N
Two planets in space gravitationally attract each other. If both the masses and distances are doubled, the force between them is
does not change
You experience weightlessness
in the absence of a supporting surface in a freely falling elevator momentarily when you step off a chair *all of the answers are correct*
two objects move toward each other due to gravity. as the objects get closer and closer, the force between them
increases
When the distance between two stars decreases by one third, the force between them
increases to nine times as much