PRELIMS Flashcards
An action: push or a pull
Force
A force ____/____ on an object
acts/exerts
A force requires a cause: an _____.
agent
A force can be either a contact or a long-range force. True or False?
True
When you are pulling a rope attached to a box, what is the agent? The rope or the box?
The rope
When forced are exerted on an object,they combine to form a _______.
Net Force
What does the triple parallel horizontal lines mean?
“is defined as”
What do you call the summation of forces?
Superposition of forces
The pull of a planet on an object or near the surface is called what?
Gravitational Force
What is the agent for the gravitational force?
The entire planet
Gravity acts on an object, whether moving or at rest. True or False?
True
What is the symbol for gravitational force?
F with an arrow above it the sub big G. (F_G)
The gravitational force always points vertically or horizontally downward?
Vertically
A force with a symbol F sub Sp.
Spring Force
A spring can push when?
compressed
A spring can pull when compressed. True or False?
False. A spring can pull when it is stretched.
A contact force that is exerted when a spring or wire pulls an object. Represented by a captial T with arrow above it.
Tension Force
What is the direction of the tension force?
Always along the direction of the rope or spring.
In Ball-and-Spring model of solids, solids are represented by what array and connected by springs?
Array of Balls.
What force does the stretched or compressed bonds exert?
Spring Forces
The force exerted perpendicular to a surface (the agent) against an object that is pressing against the surface.
Normal Force (n)
Like the Normal Force, it is the force exerted by the surface.
Friction.
If the normal force is always perpendicular to the surface, the friction force is always _____ to the surface.
Parallel
What are the two kinds of friction?
Kinetic and Static Friction
denoted by f sub k.
Kinetic Friction
A type of friction that appears as an object slides across a surface.
Kinetic Friction
Kinetic Force opposes the motion. True or False?
True
The friction force vector points in a direction _____ the velocity vector.
opposite
Denoted as f sub s.
Static Friction
It points to the direction necessary to prevent motion.
Static Friction
One example of a resistive force.
friction at a surface
The resistive force of fluid is called ____.
Drag
F sub drag is the symbol of what?
A resistive force called drag.
Like kinetic friction, it points to the opposite direction of motion.
Drag
Neglect air resistance unless asked.
Okay.
The force that occurs when a jet or rocket engine expels gas molecules at high speed.
Thrust
No special symbol for thrust so we call it ____.
F sub thrust with arrow on the top.
Electricity and magnetism, like gravity, exert contact forces or long-range forces?
Long-rage forces.
The acceleration is _______ proportional to the object’s mass.
Inversely
The amount of matter an object contains.
Mass
The more matter an object has, the more it resists accelerating in response to a force. True or False.
True
The tendency of an object to resist a change in its velocity is called ____.
Inertia
A measure of an object’s resistance to changing its motion is called inertial mass. True or False?
True.
What is Newton’s Second Law of Motion?
An object accelerates in the direction of the net force vector.
formula of acceleration (a)
Fnet over m
A ____ is an interaction between 2 objects.
force
“For every action there is an equal but opposite reaction.”
Newton’s Third Law
An object at rest is in a _____ state.
Natural
Define mechanical equilibrium
An object at rest or at motion at constant velocity with zero net force is called Mechanic Equilibrium.
There is a object/cause needed for an object to move. True or False?
False. Force is what causes an object to change its velocity.
Formula for net force.
Mass times acceleration
The natural state of an object is not rest but is uniform motion with constant velocity.
Rest is v = 0
A reference frame in which Newton’s first law is valid.
Inertial Reference Frame
True or False. Accelerating reference frames are not inertial references frame.
True
Forces exist the point of contact above the agent and the object experiencing the force. True or False.
False. *Between the agent and the object.
(except for the few special cases of long-range forces)
A quantity that is fully described by a single number (with units)
Scalar Quantity
Mass(m) and Volume (V) are examples of what quantity?
Scalar Quantity
A quantity having both a size and a direction is called a vector. True or False.
True.
What is the mathematical term for the length, or size, of a vector?
Magnitude
A quantity having a magnitude and a direction.
Vector Quantity
What is the geometric representation of a vector?
An arrow.
The magnitude of a vector is a?
Scalar
The straight-line connection from the initial to the final position.
Displacement
The sum of two vectors.
Resultant Vector
The tip-to-tail method for adding vectors.
Graphical Addition
Formula to find the angle.
arccos (A²+C²-B²/2AC)
An artificially imposed grid that you place on a problem to make quantitative measures.
Coordinate System
Velocity, Acceleration, and Forces.
Examples of Vector Quantity
