Chap 5 - Forces & Motion Flashcards
Kinematics
The branch of mechanics that deals with describing motion without consideration to forces.
Dynamics
The branch of mechanics that deals with the effects of forces upon the motion of bodies.
Mechanics
The branch of physics that encompasses both kinematics and dynamics.
“the agent”
an object that applies a given force
“the agent” for the force called “weight”
The Earth
(assuming you are on Earth)
Long range force
A force that can act at a distance
(gravity, magnetic force, etc)
contact force
a force that requires two object to touch.
“Touch, Gravity, Friction”
The main three places we will look for forces.
Net force
The sum of all the vector forces on an object.
Net force is sometimes called the ___________ force
resultant
Tension Force
The force applied by a stretched object.
Most commonly a string or a spring.
In physics and math, “normal” means
“perpendicular to”
Kinetic Friction
The force that retards the relative motion of two objects in contact.
Static Friction
The force that keeps an object “stuck” and prevents relative motion between two surfaces.
microscopic atomic model
a model of what is going on in a substance at the atomic level.
Drag
The resistive force of a fluid.
(Drag is a type of friction)
Thrust
A common force produced by a rocket or jet engine.
A constant net force causes a
constant acceleration
mass
the amount of matter an object contains
(The SI unit for mass is the kg)
The SI unit of force
“newtons”
Interaction
When two objects have an effect upon each other
Forces ALWAYS come in _______.
Pairs (always)
An interaction will always include _______ forces.
Two
(forces come in pairs - ALWAYS)
An object upon which all forces are balanced is in ________ _______.
Mechanical Equilibrium
Static Equilibrium
An object in mechanical equilibrium that is also at rest.
Dynamic Equilibrium
An object in mechanical equilibrium that is in motion
(must have constant velocity)
An object needs __________ for why it remains at rest.
no explanation
An object in motion needs ___________ for why it remains in motion.
no explanation
An object that is accelerating needs ___________ for why it is acceleration
an explanation
(the explanation would be some sort of net force)
An accelerating reference frame is also known as
a “non-inertial” reference frame.
A frame of reference traveling at a constant velocity is known as
an “inertial reference frame.”
In a non-inertail reference frame, Newton’s Laws ______________
DO NOT APPLY
Every force has ____________.
An “agent”
Free Body Diagram
A diagram that shows all the forces acting upon a single object.
Mathematical statement of Newton’s Second Law
