Download Clicker 5

Document related concepts

Centripetal force wikipedia , lookup

Gravity wikipedia , lookup

Transcript
Conceptual Integrated Science—Chapter 5
Gravity was discovered by
A.
B.
C.
D.
Aristotle.
Galileo.
Isaac Newton.
early humans.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Gravity was discovered by
A.
B.
C.
D.
Aristotle.
Galileo.
Isaac Newton.
early humans.
Explanation:
Early humans discovered gravity. Newton’s discovery was that
gravity is universal—existing everywhere.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The concept of free-falling objects applies to
A.
B.
C.
D.
apples.
the Moon.
both of the above.
neither of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The concept of free-falling objects applies to
A.
B.
C.
D.
apples.
the Moon.
both of the above.
neither of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
If the distance between two planets doubles, the force of
gravity between them
A.
B.
C.
D.
doubles.
quadruples.
decreases by half.
decreases by one-quarter.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
If the distance between two planets doubles, the force of
gravity between them
A.
B.
C.
D.
doubles.
quadruples.
decreases by half.
decreases by one-quarter.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
If the distance between two planets decreases to half, the
force of gravity between them
A.
B.
C.
D.
doubles.
quadruples.
decreases by half.
decreases by one-quarter.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
If the distance between two planets decreases to half, the
force of gravity between them
A.
B.
C.
D.
doubles.
quadruples.
decreases by half.
decreases by one-quarter.
Explanation:
Twice as close means four times the force (inverse-square law).
Can you see that if the distance were instead doubled, the force
would be one quarter?
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When the distance between two stars decreases by
one-tenth, the force between them
A.
B.
C.
D.
decreases by one-tenth.
decreases by one-hundredth.
increases 10 times as much.
increases 100 times as much.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When the distance between two stars decreases by
one-tenth, the force between them
A.
B.
C.
D.
decreases by one-tenth.
decreases by one-hundredth.
increases 10 times as much.
increases 100 times as much.
Explanation:
This refers to the inverse-square law of gravity. Ten times closer
means 100 times the force. Can you see if the distance were
increased by ten the force would be 1/100?
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Consider light from a candle. If you’re five times as far
away, its brightness will look about
A.
B.
C.
D.
one-fifth as much.
One-tenth as much.
one twenty-fifth as much.
the same brightness at any reasonable distance.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Consider light from a candle. If you’re five times as far
away, its brightness will look about
A.
B.
C.
D.
one-fifth as much.
one-tenth as much.
one twenty-fifth as much.
the same brightness at any reasonable distance.
Explanation:
Five times as far, according to the inverse-square law, is 1/25 the
brightness. Likewise for the sound of a chirping cricket!
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Consider a space probe at a distance five times Earth’s
radius. Compared with gravitational force at Earth’s
surface, its gravitational attraction to Earth at this distance
is about
A.
B.
C.
D.
one-fifth as much.
one-tenth as much.
one twenty-fifth as much.
the same gravitation at any reasonable distance.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Consider a space probe at a distance five times Earth’s
radius. Compared with gravitational force at Earth’s
surface, its gravitational attraction to Earth at this distance
is about
A.
B.
C.
D.
one-fifth as much.
one-tenth as much.
one twenty-fifth as much.
the same gravitation at any reasonable distance.
Explanation:
Five times as far (inverse-square law) means 1/25 the gravitational
attraction.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
If the Earth’s radius somehow shrunk, your weight on the
shrunken surface would be
A.
B.
C.
D.
less.
more.
unchanged.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
If the Earth’s radius somehow shrunk, your weight on the
shrunken surface would be
A.
B.
C.
D.
less.
more.
unchanged.
none of the above.
Comment:
The idea of surface force increasing when a star shrinks leads to
the huge forces near an ultimate shrunken star—a black hole.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
If the Sun were twice as massive, its pull on Earth would be
A.
B.
C.
D.
unchanged.
twice.
half.
four times as much.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
If the Sun were twice as massive, its pull on Earth would be
A.
B.
C.
D.
unchanged.
twice.
half.
four times as much.
Explanation:
Let the equation for gravity guide your thinking. When one mass is
doubled, with all else being the same, the force doubles.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Strictly speaking, compared with your weight on the
ground, your weight at the top of a very tall ladder would be
A.
B.
C.
D.
less.
more.
no different, really.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Strictly speaking, compared with your weight on the
ground, your weight at the top of a very tall ladder would be
A.
B.
C.
D.
less.
more.
no different, really.
none of the above.
Explanation:
This follows from the inverse-square law.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
According to the equation for gravity, if you travel far
enough from Earth, the gravitational influence of Earth will
A.
B.
C.
D.
reach zero.
still be there.
actually increase.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
According to the equation for gravity, if you travel far
enough from Earth, the gravitational influence of Earth will
A.
B.
C.
D.
reach zero.
still be there.
actually increase.
none of the above.
Explanation:
Look at the gravity equation: as d approaches infinity, F
approaches zero—but never reaches zero.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
You are weightless when you are
A.
B.
C.
D.
in free fall.
without a support force.
infinitely away from all mass.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
You are weightless when you are
A.
B.
C.
D.
in free fall.
without a support force.
infinitely away from all mass.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When an astronaut in orbit is weightless, he or she is
A.
B.
C.
D.
beyond the pull of Earth’s gravity.
still in the grip of Earth’s gravity.
in the grip of interstellar gravity.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When an astronaut in orbit is weightless, he or she is
A.
B.
C.
D.
beyond the pull of Earth’s gravity.
still in the grip of Earth’s gravity.
in the grip of interstellar gravity.
none of the above.
Comment:
If the astronaut were not in the grip of Earth’s gravity, would his or
her circling the Earth occur? Interstellar gravity plays a
significantly lesser role.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When you stand at rest on a weighing scale, the force due
to gravity on you is
A.
B.
C.
D.
equal in magnitude to the support force of the scale.
almost equal to the support force of the scale.
actually absent.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When you stand at rest on a weighing scale, the force due
to gravity on you is
A.
B.
C.
D.
equal in magnitude to the support force of the scale.
almost equal to the support force of the scale.
actually absent.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Inhabitants in the International Space Station orbiting the
Earth are
A.
B.
C.
D.
weightless.
in the grip of Earth’s gravity.
without a support force.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Inhabitants in the International Space Station orbiting the
Earth are
A.
B.
C.
D.
weightless.
in the grip of Earth’s gravity.
without a support force.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The center of gravity of an object is located at the
A.
B.
C.
D.
point of its average weight.
geometric center.
heaviest portion of the object.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The center of gravity of an object is located at the
A.
B.
C.
D.
point of its average weight.
geometric center.
heaviest portion of the object.
all of the above.
Comment:
Can you see that the center of gravity of a baseball bat is closer to
its heavier end?
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The center of gravity of your body
A.
B.
C.
D.
is located in your midsection.
varies with body position.
remains within your body.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The center of gravity of your body
A.
B.
C.
D.
is located in your midsection.
varies with body position.
remains within your body.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Centripetal force is any force that
A.
B.
C.
D.
acts on a rotating object.
produces circular motion.
pulls objects outward when they whirl about a central point.
takes the place of gravity.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Centripetal force is any force that
A.
B.
C.
D.
acts on a rotating object.
produces circular motion.
pulls objects outward when they whirl about a central point.
takes the place of gravity.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
In a future rotating space habitat, centripetal force can
provide
A.
B.
C.
D.
a steady rotational speed.
weightlessness.
a right-angle force for inhabitants.
a support force sensed as weight.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
In a future rotating space habitat, centripetal force can
provide
A.
B.
C.
D.
a steady rotational speed.
weightlessness.
a right-angle force for inhabitants.
a support force sensed as weight.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
A projectile follows a curved path
A.
B.
C.
D.
when it crosses a gravitational field.
due to a combination of constant horizontal motion and
accelerated downward motion.
called a parabola.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
A projectile follows a curved path
A.
B.
C.
D.
when it crosses a gravitational field.
due to a combination of constant horizontal motion and
accelerated downward motion.
called a parabola.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The speed of a bowling ball rolling along a smooth alley is
A.
B.
C.
D.
not affected by gravity.
constant.
both of the above.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The speed of a bowling ball rolling along a smooth alley is
A.
B.
C.
D.
not affected by gravity.
constant.
both of the above.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When no air resistance acts on a projectile, its horizontal
acceleration is
A.
B.
C.
D.
g.
at right angles to g.
centripetal.
zero.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When no air resistance acts on a projectile, its horizontal
acceleration is
A.
B.
C.
D.
g.
at right angles to g.
centripetal.
zero.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Without air resistance, the time for a vertically tossed ball to
return to where it was thrown from is
A.
B.
C.
D.
10 m/s for every second in the air.
the same as the time going upward.
less than the time going upward.
more than the time going upward.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Without air resistance, the time for a vertically tossed ball to
return to where it was thrown from is
A.
B.
C.
D.
10 m/s for every second in the air.
the same as the time going upward.
less than the time going upward.
more than the time going upward.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
With air resistance, the time for a vertically tossed ball to
return to where it was thrown from is
A.
B.
C.
D.
10 m/s for every second in the air.
the same as the time going upward.
less than the time going upward.
more than the time going upward.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
With air resistance, the time for a vertically tossed ball to
return to where it was thrown from is
A.
B.
C.
D.
10 m/s for every second in the air.
the same as the time going upward.
less than the time going upward.
more than the time going upward.
Explanation:
Consider a feather tossed upward. It reaches its zenith rather
quickly but falls back to its starting place slowly. The same is true
of a ball tossed in air, though not as pronounced.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When air resistance is negligible, the component of velocity
that doesn’t change for a projectile is the
A.
B.
C.
D.
horizontal component.
vertical component.
a combination of horizontal and vertical components.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
When air resistance is negligible, the component of velocity
that doesn’t change for a projectile is the
A.
B.
C.
D.
horizontal component.
vertical component.
a combination of horizontal and vertical components.
none of the above.
Explanation:
That’s because there is no horizontal force. What can you say
about the vertical component of velocity?
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Air resistance on a projectile
A.
B.
C.
D.
lessens its range.
lessens its height.
both of the above.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
Air resistance on a projectile
A.
B.
C.
D.
lessens its range.
lessens its height.
both of the above.
none of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The first person(s) to publish writings about Earth satellites
was
A.
B.
C.
D.
Aristotle.
Isaac Newton.
Albert Einstein.
Hewitt, Lyons, Suchocki, and Yeh.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
The first person(s) to publish writings about Earth satellites
was
A.
B.
C.
D.
Aristotle.
Isaac Newton.
Albert Einstein.
Hewitt, Lyons, Suchocki, and Yeh.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
In a circular orbit, the gravitational force on a satellite is
A.
B.
C.
D.
constant in magnitude.
at right angles to satellite motion.
a centripetal force.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
In a circular orbit, the gravitational force on a satellite is
A.
B.
C.
D.
constant in magnitude.
at right angles to satellite motion.
a centripetal force.
all of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
A satellite in elliptical orbit about Earth travels fastest when
it moves
A.
B.
C.
D.
close to Earth.
far from Earth.
in either direction—the same everywhere.
between the near and far points from Earth.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
A satellite in elliptical orbit about Earth travels fastest when
it moves
A.
B.
C.
D.
close to Earth.
far from Earth.
in either direction—the same everywhere.
between the near and far points from Earth.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
A satellite in orbit around the Earth is above Earth’s
A.
B.
C.
D.
atmosphere.
gravitational field.
both of the above.
neither of the above.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley
Conceptual Integrated Science—Chapter 5
A satellite in orbit around the Earth is above Earth’s
A.
B.
C.
D.
atmosphere.
gravitational field.
both of the above.
neither of the above.
Explanation:
Don’t say above Earth’s gravitational field! If it were, it wouldn’t
circle Earth.
Copyright © 2007 Pearson Education, Inc., publishing as Pearson Addison-Wesley