Download Gravitation

Q12.1
The mass of the Moon is 1/81 of the
mass of the Earth.
Compared to the gravitational force
that the Earth exerts on the Moon,
the gravitational force that the
Moon exerts on the Earth is
1. 812 = 6561 times greater
2. 81 times greater
3. equally strong
4. 1/81 as great
5. (1/81)2 = 1/6561 as great
A12.1
The mass of the Moon is 1/81 of the
mass of the Earth.
Compared to the gravitational force
that the Earth exerts on the Moon,
the gravitational force that the
Moon exerts on the Earth is
1. 812 = 6561 times greater
2. 81 times greater
3. equally strong
4. 1/81 as great
5. (1/81)2 = 1/6561 as great
Q12.2
The planet Saturn has 100 times the mass of the Earth and is
10 times more distant from the Sun than the Earth is.
Compared to the Earth’s acceleration as it orbits the Sun, the
acceleration of Saturn as it orbits the Sun is
1. 100 times greater
2. 10 times greater
3. the same
4. 1/10 as great
5. 1/100 as great
A12.2
The planet Saturn has 100 times the mass of the Earth and is
10 times more distant from the Sun than the Earth is.
Compared to the Earth’s acceleration as it orbits the Sun, the
acceleration of Saturn as it orbits the Sun is
1. 100 times greater
2. 10 times greater
3. the same
4. 1/10 as great
5. 1/100 as great
Q12.3
Compared to the Earth, Planet X
has twice the mass and twice the
radius.
This means that compared to the
Earth, Planet X has
1. 4 times the surface gravity
2. twice the surface gravity
3. the same surface gravity
4. 1/2 as much surface gravity
5. 1/4 as much surface gravity
A12.3
Compared to the Earth, Planet X
has twice the mass and twice the
radius.
This means that compared to the
Earth, Planet X has
1. 4 times the surface gravity
2. twice the surface gravity
3. the same surface gravity
4. 1/2 as much surface gravity
5. 1/4 as much surface gravity
Q12.4
A satellite is moving around the
Earth in a circular orbit. Over the
course of an orbit, the Earth’s
gravitational force
1. does positive work on the
satellite
2. does negative work on the
satellite
3. does positive work on the
satellite during part of the orbit
and negative work on the
satellite during the other part
4. does zero work on the
satellite at all points in the orbit
A12.4
A satellite is moving around the
Earth in a circular orbit. Over the
course of an orbit, the Earth’s
gravitational force
1. does positive work on the
satellite
2. does negative work on the
satellite
3. does positive work on the
satellite during part of the orbit
and negative work on the
satellite during the other part
4. does zero work on the
satellite at all points in the orbit
Q12.5
A planet (P) is moving
around the Sun (S) in an
elliptical orbit. As the
planet moves from
aphelion to perihelion, the
Sun’s gravitational force
1. does positive work on the planet
2. does negative work on the planet
3. does positive work on the planet during part of the motion
from aphelion to perihelion and negative work on the planet
during the other part
4. does zero work on the planet at all points between aphelion
and perihelion
A12.5
A planet (P) is moving
around the Sun (S) in an
elliptical orbit. As the
planet moves from
aphelion to perihelion, the
Sun’s gravitational force
1. does positive work on the planet
2. does negative work on the planet
3. does positive work on the planet during part of the motion
from aphelion to perihelion and negative work on the planet
during the other part
4. does zero work on the planet at all points between aphelion
and perihelion
Q12.6
A planet (P) is moving
around the Sun (S) in an
elliptical orbit. As the
planet moves around the
orbit, the planet’s angular
momentum
1. increases as it moves from aphelion to perihelion and
decreases as it moves from perihelion to aphelion
2. decreases as it moves from aphelion to perihelion and
increases as it moves from perihelion to aphelion
3. increases at all times
4. decreases at all times
5. remains the same at all times
A12.6
A planet (P) is moving
around the Sun (S) in an
elliptical orbit. As the
planet moves around the
orbit, the planet’s angular
momentum
1. increases as it moves from aphelion to perihelion and
decreases as it moves from perihelion to aphelion
2. decreases as it moves from aphelion to perihelion and
increases as it moves from perihelion to aphelion
3. increases at all times
4. decreases at all times
5. remains the same at all times
A satellite orbits the earth with constant speed at height
above the surface equal to the earth’s radius. The
magnitude of the satellite’s acceleration is
1.
-gon earth.
2.
gon earth.
3. gon earth.
4. 2gon earth.
5. 4gon earth.
A satellite orbits the earth with constant speed at height
above the surface equal to the earth’s radius. The
magnitude of the satellite’s acceleration is
1.
-gon earth.
2.
gon earth.
3. gon earth.
4. 2gon earth.
5. 4gon earth.
The figure shows a binary star system.
The mass of star 2 is twice the mass of
star 1. Compared to
, the magnitude
of the force
is
1. one quarter as big.
2. half as big.
3. twice as big.
4. four times as big.
5. the same size.
The figure shows a binary star system.
The mass of star 2 is twice the mass of
star 1. Compared to
, the magnitude
of the force
is
1. one quarter as big.
2. half as big.
3. twice as big.
4. four times as big.
5. the same size.
A planet has 4 times the mass of the earth, but the
acceleration due to gravity on the planet’s surface is the
same as on the earth’s surface. The planet’s radius is
1.
Re.
2.
Re.
3.
Re.
4. 2Re.
5. 4Re.
A planet has 4 times the mass of the earth, but the
acceleration due to gravity on the planet’s surface is the
same as on the earth’s surface. The planet’s radius is
1.
Re.
2.
Re.
3.
Re.
4. 2Re.
5. 4Re.
Rank in order, from largest to smallest, the absolute
values |Ug| of the gravitational potential energies of these
pairs of masses. The numbers give the relative masses
and distances.
In absolute value:
1. Ue > Ua = Ub = Ud > Uc
2. Ub > Uc > Ua = Ud > Ue
3. Ub > Uc > Ud > Ua > Ue
4. Ue > Ua = Ub >Uc > Ud
5. Ue > Ud > Ua > Ub = Uc
Rank in order, from largest to smallest, the absolute
values |Ug| of the gravitational potential energies of these
pairs of masses. The numbers give the relative masses
and distances.
In absolute value:
1. Ue > Ua = Ub = Ud > Uc
2. Ub > Uc > Ua = Ud > Ue
3. Ub > Uc > Ud > Ua > Ue
4. Ue > Ua = Ub >Uc > Ud
5. Ue > Ud > Ua > Ub = Uc
Two planets orbit a star. Planet 1 has orbital radius
r1 and planet 2 has r2 = 4r1. Planet 1 orbits with
period T1. Planet 2 orbits with period
1.
2.
3.
4.
5.
T2 = T1/2.
T2 = T1.
T2 = 2T1.
T2 = 4T1.
T2 = 8T1.
Two planets orbit a star. Planet 1 has orbital radius
r1 and planet 2 has r2 = 4r1. Planet 1 orbits with
period T1. Planet 2 orbits with period
1.
2.
3.
4.
5.
T2 = T1/2.
T2 = T1.
T2 = 2T1.
T2 = 4T1.
T2 = 8T1.
Chapter 12
Reading Quiz
Who discovered the basic laws of planetary orbits?
1. Newton
2. Kepler
3. Faraday
4. Einstein
5. Copernicus
Who discovered the basic laws of planetary orbits?
1. Newton
2. Kepler
3. Faraday
4. Einstein
5. Copernicus
What is geometric shape of a planetary or satellite orbit?
1.
2.
3.
4.
5.
Circle
Hyperbola
Sphere
Parabola
Ellipse
What is geometric shape of a planetary or satellite orbit?
1.
2.
3.
4.
5.
Circle
Hyperbola
Sphere
Parabola
Ellipse
The gravitational force between two objects of masses
m1 and m2 that are separated by distance r is
1. proportional to r.
2. proportional to 1/r.
3. proportional to 1/r2.
4. (m1 + m2)g.
5. (m1 + m2)G.
The gravitational force between two objects of masses
m1 and m2 that are separated by distance r is
1. proportional to r.
2. proportional to 1/r.
3. proportional to 1/r2.
4. (m1 + m2)g.
5. (m1 + m2)G.
The value of g at the height of the
space shuttle’s orbit is
1. 9.8 m/s2.
2. slightly less than 9.8 m/s2.
3. much less than 9.8 m/s2 .
4. exactly zero.
The value of g at the height of the
space shuttle’s orbit is
1. 9.8 m/s2.
2. slightly less than 9.8 m/s2.
3. much less than 9.8 m/s2.
4. exactly zero.