Mod. 4 - Lesson 1 (Force And Motion) Flashcards
Force
A push or pull
Magnitude
Distance or quantity
The symbol F is…
A vector notation that represents the size and direction of a force
The magnitude of a force is measured in what units?
Newtons (N)
All accelerations are…
The result of an unbalanced force acting on an object
System
Object(s) that can interact with each other or the external world
External world
Anything the system can interact with
Contact force
When something from the external world touches the system (it exerts a force on it)
Field forces
Exerted without contact
Ex: gravitational force
Agent
The specific and identifiable cause of contact or field force
Ex: your hand (agent) exerting a force on a book (system)
A force does not exist if?
There is not both an agent and a system
Free body diagram
A physical representation that shows the forces acting in a system
All accelerations are?
The result of unbalanced forces
If a motion diagram shows that an object is accelerating, a free body diagram of that object should have an unbalanced force..?
In the same direction as the acceleration
When you push in the table on the table in opposite directions with the same amount of force, there is no unbalanced force, so…
The table does not accelerate but remains at rest
Net force
The vector sum is all the forces on an object
y=kx+b
The y intercept is 0 so it simplifies to y=kx. The y variable is acceleration. The x variable is force. Therefore acceleration is equal to the slope of the line multiplied by the applied net force
a=Fnet/m
Acceleration = Net force / mass
(Newtons second law)
Fnet=ma
Force net (newton) = mass times acceleration
Net force
Sum of all forces acting on a system
Newton’s second law
States that the acceleration of an object is proportional to the net force and inversely proportional to the mass of the object being accelerated
Newton’s first law
An object that is at rest will stay at rest and an object will stay in motion unless acted on by another force
If acceleration equals zero
Then velocity does not change
Newton’s second law says that if Fnet = 0
Then acceleration equals 0
Inertia
The tendency of an object to resist changes in velocity
Equilibrium
If the net force on an object is zero
If it is moving at a constant velocity (velocity doesn’t change)
(A net force disturbs a state of equilibrium)
