velocity is a vector quantity,the magnitude of velocity is called speed.
Vave = delta x / delta t
average velocity and instantaneous velocity
Newton's Law
Newton's First Law: If the total force acting on an object is zero, the
object will maintain its velocity forever.
Newton's Second Law: In many situations,
several different forces act on an object
simultaneously. the total force on the object is the sum of these individual forces. The acceleration of an object with mass m is given by: a = F / m.
When one object exerts a force on a second object, the second object exerts a force
of the same magnitude and opposite direction on the first object.
all action come in action-reaction pairs.
Chapter 3: Forces and Motion in One Dimension
Part 1: constant acc. equations of motion, normal forces and weight, free body diagrams
Motion Along a Line
(Vfx)=(Vix) + (Ax)(T)
X= (Vix)(T) + (1/2) (Ax)(T)^2
(Vfx)^2= (Vix)^2 + (2)(Ax)(X)
Normal Force
Acts perpendicularly to the plane of contact
Apparent Weight= Normal Force
Free Body Diagram
Used for analysis using Newton's 2nd Law
Friction
Opposes the Motion
Kinetic Friction: F(friction)= (coefficient of kinetic friction) x N (normal force)
Static Friction: F (friction)= less than/ equal to= (coefficient of static friction) x N (normal force)
Part 2: free fall motion, Newton's 2nd Law applications
Free fall motion
any object which once projected or dropped continues in motion by its own inertia and is influenced only by the down force of gravity
object always has acceleration of gravity: 9.8 m/s^2
Tension
the ideal "cord" has zero mass, does not stretch, and tension is the same throughout the cord
Chapter 4
Ch4.1 static
ΣF(F-net)=ma
When forces are balanced their is no acceleration in the system
this is called static equilibrium
Which also means if there is no acceleration the is no un-balanced force F-net=0
Projectile Motion
X-component of velocity is always constant in projectile motion unless friction force is present.
The Y-component of velocity is always zero at its peak hieght
Always acted on by gravity if going up (negative acceleration) if going down (positive acceleration)
Range: is the total distances the object can cover in the X-direction
can be calculated by taking the X-component of the velocity and multiplying it by 2x the
time it takes an object to reach its peach in (not including height differences or dead drops)