chapter 2
When a planet is seen at opposition, it is always
at its closest point to the Earth.
In the geocentric model of the solar system developed by Ptolemy,
the planets move in circular epicycles while the centers of the epicycles move in circular orbits around the Earth.
Kepler's second law states:
A line joining a planet to the Sun sweeps out equal areas in equal times.
Kepler's third law can be described in which of the following ways?
The larger the orbit, the longer it takes for the planet to complete one revolution.
Two spaceships that have different masses but rocket engines of identical force are at rest in space. If they fire their rockets at the same time, which ship will speed up faster?
The one with the lower mass
What is the difference between the synodic and sidereal periods of a planet?
The synodic period refers to the planet's period with respect to the Earth's motion, whereas the sidereal period is the true period with respect to the background stars.
An unbalanced force acting on an object will ALWAYS cause it to
Whenever some object A exerts a force on some other object B, B must exert a force of equal magnitude on A in the opposite direction.
Which of the following statements is a CORRECT version of Newton's third law?
Whenever some object A exerts a force on some other object B, B must exert a force of equal magnitude on A in the opposite direction.
When observing planetary motions from the Earth, the phrase "retrograde motion" refers to
a slow westward motion of the planet from night to night compared to the background stars.
When Mars is at opposition, it is
high in the sky at midnight.
According to Newton's first law,
if no net force is acting upon an object, then both the object's speed and direction of travel will be constant.
Kepler's first law states that a planet moves around the Sun
in an elliptical orbit, with the Sun at one focus.
Kepler's second law states that a planet moves fastest when it
is closest to the Sun.
When Venus is at superior conjunction,
it is at its greatest distance from the Earth.
The phenomenon of parallax is
the change in apparent position of a nearby object compared to background objects as a result of the motion of the observer.
Galileo's early observations of the sky with his newly made telescope included
the discovery of the phases of Venus.
The semimajor axis of an ellipse is
the distance from the center of the ellipse to one end, along the largest diameter of the ellipse.
The force of gravity between two objects is proportional to
the product of their masses.
The acceleration of an object is defined as
the rate of change of its velocity.
the square of a planet's period in years is the same number as the cube of its semimajor axis in AU.
the square of a planet's period in years is the same number as the cube of its semimajor axis in AU.
A person standing on a bathroom scale sees a reading on the scale of 148 pounds. This person is acted on by
two forces of equal size acting in opposite directions.
The Copernican system for planetary motions is
Sun-centered, with the planets moving in perfect circles around the Sun.
Which fundamental particle is believed to create the physical property called "mass" when it interacts with other particles?
The Higgs particle
Which of the following four objects or persons is NOT accelerating?
An Olympic swimmer exerting considerable force to maintain a constant speed in a straight line through the water
Which of the following statements CORRECTLY states the significance of Galileo's observation that Jupiter has satellites (moons)?
It showed that bodies can orbit an object other than the Earth.
How was the planet Neptune discovered?
It was discovered by mathematical prediction using Newton's laws.