reference text: Giancoli, Douglas C. Physics. 5th Ed. Ed. Paul F. Corey. Upper Saddle River: Prentice Hall, 1998.

Physics Explained

If you need a general summary of physics, stay here.  Detailed outlines are on the "Physics Outlines" page and my priceless advce is on the "Physics Advice" page.  Simple. 

SUMMARY 

MECHANICS

Speed, Displacement, Velocity

 

*SCALARS are basically just normal numbers.  They ahve a MAGNITUDE  (fancy name for number value) but NO DIRECTION; Speed is a scalar.

 

*VECTORS have a MAGNITUDE and a DIRECTION.

 

When adding vectors, break each into their hroizontal and vertical components using sin and cos, then add the horizontal components, and the vertical compenents, so that you have one horizonatal and one vertical componenet.  Then use  a² + b² + c²  to find the length of the final vector sum.  

 

 An easy way to find the direction is to use the parallelogram rule--connect the vectors tail-to-tail, then make a parallelogram of them by drawing 2 lines parallel to the originals.  The diagonal is the direction.

 

AVERAGE SPEED = total distance / total time= s = d / t

 

if you graph distance vs. time, the slope is distance/ tome, which is speed.

the derivative is slope at a given point  (calculus stuff, but IB seems to like the concept. 

 

DISPLACEMENT is how far something is from the starting point, the shortest line you can draw between a start and end point.

Say you run a lap on a circular track.  Your displacement is zero because you ended where you started.

 

VELOCITY is speed in a given direction;  so it is a Vector.

 

average velocity = displacement / time = v = d/t

 

MOTION EQUATIONS:

acceleration = change in velocity/ time interval

distance equation:  d = v_ot + ½at²   

                             v_f² = v_o² + 2ad 

Force of Friction = (coefficient of friction) (normal force) 

If something is on an inclined plane, THE NORMAL FORCE IS THE COMPONENT OF THE WEIGHT THAT'S PERPENDICULAR TO THE SLOPE!

 

Energy

Potential energy = mgh

Kinetic energy = ½mv²

Spring PE =  ½kx²   

Thermo 

Isobaric = constant pressure

Isochoric/isovolumetric = constant volume

Adiabatic = no heat flows in/out of system

Ideal gas law:  PV = nRT

P = absolute pressure

V = volume

n = # of moles

R =   gas constant

T = Kelvin temperature

P₁V₁/T₁ = P₂V₂/T₂

 Work done compressing a gas isobarically = PΔV

Calorimetry

no total change in heat (delta Q = 0)

Q + Q = 0

heat gained + heat lost = 0

mcΔt + mL... -(mcΔt + mL...) = 0