Read Chapter 4
2.) Provide an example of "free fall"
3.) According to Newton's 3rd Law,
a.) The Earth's gravitational pull on the Sun is greater than the Sun's
gravitational pull on the Earth
b.) The Sun's gravitational pull on the Earth is greater than the Earth's
gravitational pull on the Sun
c.) The Earth's gravitational pull on the Sun is equal in magnitude
to the Sun's gravitational pull on the Earth
4.) Asteroid "Zot", a fictional asteroid in our
solar system, is traveling on an extremely eccentric orbit.
During Asteroid Zot's trip around the Sun,
a.) Asteroid Zot's speed is constant
b.) Asteroid Zot's velocity is constant
c.) Asteroid Zot's momentum is constant
d.) Asteroid Zot's angular momentum is constant
e.) the Sun's gravitational force on Asteroid Zot is constant
5.) In Asteroid Zot's orbit (from the previous question):
a.) The distance between Asteroid Zot and the Sun is constant
b.) Asteroid Zot's potential energy is constant
c.) Asteroid Zot's speed is constant
d.) Asteroid Zot's kinetic energy is constant
e.) Asteroid Zot's kinetic energy plus potential energy is constant
6.) Asteroid "Zerf" is on a perfectly circular orbit around the
Sun. Why doesn't the Sun's gravitational pull cause a 'twisting
force' (or torque) that would speed up Asteroid Zerf?
7.) Which has more thermal energy per gallon:
a.) a pot of boiling water (temperature = 212 degrees Fahrenheit)
b.) the air inside a warm oven (temperature = 212 degrees Fahrenheit)
c.) both have the same amount of thermal energy per gallon
8.) Fill in each blank with a type of energy.
a.) The rocket's fuel was burned in order to speed up the rocket.
This is an example of converting ________ energy to _______ energy.
b.) After the fuel was exhausted and while the rocket was still
moving away from the Earth, it slowed as it moved further from the
Earth. This is an example of _________ energy being converted into
__________ energy.
c.) The rocket was powered by a nuclear engine, which consumed atoms
and heated the bath around the hydrogen chamber. This is an example
of _________ energy being converted into __________ energy.
d.) The rocket also had a solar panel, which collected sun light in order
to charge a battery. This is an example of converting _________ energy
into __________ energy.
9.) Consider a binary star system in which each star has the same
mass and radius as the other.
a.) Where is the center of mass of the binary star system?
c.) If each star's mass is equal to 1030 kilograms, and each
of the stars is located 1012meters from the point about which
it orbits. How long does it take for each star to make a complete
orbit? Hint: use the general form of Kepler's Third Law, which
is p2 =
(4 pi2 a3) / (G (M1 + M2) ),
where G = 6.67 x 10-11 m3/kg/sec2,
second hint: the "exp" key on your calculator is equivalent
to "10 to the". So, to key in 1030, you key in
"exp" "30".
If you were to key in "10" "x" "exp" "30", you would
have 1031, which wouldn't be what you intended.
Note: We did not cover the material after this point.
Thus, you do not need to solve the following problems or
study them for the first midterm.
10.) Regarding bound and unbound orbits:
a.) What is the difference between a bound orbit and an unbound
orbit?
b.) If there is an object on a bound orbit around the Sun and you want
to change its orbit to make it an unbound orbit, do you need to
give it energy or take away some of its energy?
11.) Tides on Earth are caused by:
a.) winds pushing water
b.) the Moon's gravitational attraction
c.) the Earth rotating slower than the synchronous rotation rate
d.) all of the above
e.) none of the above
12.) Why does the same side of the Moon face the Earth, 24 hours a day, 365 days a year?