Basics
Isaac Newton
Identifying Forces
Balanced forces vs Unbalanced forces and Incline plane
Friction
100
What are the forces necessary for?
Forces is necessary for causing acceleration or changing an object's state of motion
100
How many laws are there?
3
100
What is Fg?
Force due to gravity (weight): present whenever the Earth or a planet is near another object
100
What is the net force and acceleration of balanced forces?
Net Force = 0N and Acceleration= 0 m/s2
because object is either at rest or moving at constant velocity
100
What is the friction caused by?
Microscopic contact points adhere to one another
200
What are forces not necessary for?
Forces are not necessary for maintaining an object's state of motion.
200
What are the 3 laws called?
Law of inertia, Force law, and Action-Reaction law
200
What is FN？
Normal force: Force of an immovable object
Drawn perpendicular to the surface
200
What is the net force and acceleration of unbalanced forces?
Net force and acceleration are greater than 0( N or m/s2).
because Object is accelerating in the direction of the Net Force
200
Describe static friction.
Forces preventing surfaces from moving relative to each other
Value varies with the applied force
Equal to applied force (net force is zero) up to a maximum amount of force (Ffsmax)
After this amount, the object begins to move
300
What are the natural states of motion?
At rest and moving at constant velocity
300
what's the first law?
Law of Inertia: an object remains at rest or at a constant velocity unless acted on by unbalanced forces.
300
What is FA?
Applied force: present when a person or machine exerts a force on an object
300
What happens when the box is in equilibrium?
If the box is in equilibrium, then the forces are balanced (which means the box is either at rest or constant velocity).
Fgll=Ff
Fg(perpendicular)=FN
300
Describe kinetic friction.
Force resisting motion when surfaces are sliding relative to each other
Amount of kinetic friction is less than maximum amount of static friction
Amount of kinetic friction remains constant doesn't depend on applied force
400
What is a free body diagram?
A “free-body diagram” is a diagram that shows all the forces acting on an object
400
What is the second law?
Forces Law: when unbalanced force act on an object, the object accelerates in the direction of the resultant force
400
What is FT?
FT: Force of tension: preset whenever a rope, string, or cable pulls on an object
400
What happens when the box is not in equilibrium?
If the box is not in equilibrium, then the forces are not balanced (which mean the box is accelerating)
Fnet =Fgll-Ff
Fg(perpendicular)=FN
400
Describe the coefficient of friction.
The measure of the relative roughness between two surfaces
Always constant for any two objects in contact
500
List at least 3 formulas used in this unit.
500
What is the 3rd law?
Action-Reaction Law: the force that A exerts on B us equal and opposite to the force that B exerts on A.
(For every Action Force there is a equal and opposite Reaction Force)
500
What is Ff?
Ff: Force of friction: present between two surfaces that touch
Always acts in the opposite direction of motion
500
What happens as the angle increases?
As angle increase,
Weight stays the same
Fg=mg
Normal force decreases
Fg(perpendicular)= FN
Force of friction decreases
Ff=uFN
Coefficient of friction always stays constant
500
What are the 2 types of coefficient o frictions and describe them.
Coefficient of static friction: used to get the object to move
Coefficient of kinetic friction: used when the object is moving