Definitions
The tendency of matter to do what it is doing
Inertia
If the net force acting on an object is zero, the object is not accelerating.
Newton's Second Law
Force = 10 N
acceleration = 2 m/s2
Mass = ?
5 kg
the amount of matter in an object
mass
the force related to surfaces that acts perpendicular to the surface
Normal Force
sum of all forces equals zero
equilibrium
If I push on the wall, the wall pushes back.
Third
mu = .5
Ff = 20 N
FN = ?
40 N
ratio of force of friction to normal force
coefficient of friction
The attraction of the earth for a mass
Force of gravity or Weight
The units of the coefficient of friction
NO UNITS!
Objects like to keep doing what they are doing.
First
What is the mass of an object on earth that weighs 490 Newtons?
50 kg
rate of change of velocity
acceleration
Opposes the direction of motion, or impending motion.
Friction
9.8 m/s2
acceleration due to gravity on earth
A bowling ball takes more force to get moving than a baseball.
First
A force of 50 N is applied at 30o North of East
What is its Eastern component?
43 N
mass x acceleration due to gravity
Weight or Force of gravity
Force in a rope, thread or chain
Tension
this is a diagram of all of the forces acting ON and object
Free Body Diagram
Acceleration depends on the sum of all forces acting on an object.
Second
A 980 Newton llama stands on a scale in an elevator that is accelerating upwards at 2 m/s2.
What does the scale read?
1180 Newtons
my units are kg-m/s2
Force (Newton)
Sum of all forces acting on an object
Net Force