2:3 Forces on Systems
Which of Newton's Laws states that for every action, there is an equal and opposite reaction?
Third Law of Motion
Newton's Law of Universal Gravitation states that the force of gravity between two objects depends on their masses and the _______ between them.
distance
What is an orbit?
The curved path of one object, like a planet or satellite, around another object in space.
Kepler's First Law of Planetary Motion states that planets orbit the Sun in paths shaped like:
ellipses.
Coulomb's Law is used to calculate the force between which of the following?
Two electric charges
A book is resting on a table. The "action" force is the Earth pulling down on the book (its weight). What is the "reaction" force?
The book pulling up on the Earth
If the distance between two objects increases, the gravitational force between them will:
decrease.
What is the primary force responsible for keeping the Moon in orbit around the Earth?
Earth's gravitational pull
According to Kepler's Second Law, a planet moves _______ when it is closer to the Sun.
faster
According to the fundamental rule of electric charge, "like charges ______ and opposite charges ______."
repel, attract
A diagram that shows all the forces acting on a single object is called a:
Free-body diagram
The constant 'G' in the Universal Gravitation formula (Fg=Gr2m1m2) is known as the:
Universal Gravitational Constant.
A satellite is any object that:
orbits a larger object.
Kepler's Third Law describes the relationship between a planet's orbital period and its
distance from the Sun (orbited object)
If the distance between two charged objects is doubled, the electric force between them will:
become one-quarter (1/4) as strong.
An object is in equilibrium when the net force acting on it is:
Zero
Which of the following pairs of objects would have the strongest gravitational attraction, assuming they are all the same distance apart?
A person and a book
The Earth and the Moon
Two bowling balls
The Sun and the Earth
The Sun and the Earth
An object in a stable orbit is in a state of continuous: (2 correct answers)
free fall & acceleration towards the central body
The "orbital period" of a planet is the time it takes to:
complete one full orbit around the Sun.(orbited object)
What is the standard unit of electric charge?
Coulomb (C)
When a cannon fires a cannonball, the cannon moves backward. This is an example of which law?
Newton's Third Law
Gravity is a force that is always:
attractive.
The speed a spacecraft needs to travel to break away from a planet's gravitational pull is called:
escape velocity.
According to Kepler's First Law, the Sun is located at one of the two _______ of a planet's elliptical orbit.
foci
The subatomic particle that carries a negative electric charge is the:
electron.