Zusammenfassung der Ressource
Physics 2010 Group 5A: Concept Map 1
- Chapter 1
- The Purpose of Physics
- Physics: the science
of matter and energy,
and the interactions
between them
- Problem Solving
- Types of Problems
- Quantitative problems
- Concept checks
- Reasoning and relationship problems
- Problem Solving Strategies
- KUDOS Method
- K = Known
- U = Unknown
- D = Definition
- O = Output
- S = Substantiation
- Dealing With Numbers
- Scientific Notation
- A way to abbreviate very large or very small numbers
- Example: Diameter of a proton = 1 x 10^-15 meters
- Significant Figures
- The most basic way to indicate accuracy of a quantity
- 1. Nonzero digits are always significant
- 2. Final ending zeroes to the right are significant
- 3. Placeholder zeroes are not significant
- 4. Zeroes between digits are significant
- SI System of Units
- Standard Units of Dimensions
- Length = meter (m); Mass = kilogram (kg); Time = seconds (s)
- Unit Prefixes
- tera (T) = 10^12; giga (G) = 10^9; mega (M) = 10^6; kilo (k) = 10^3
- centi (c) = 10^-2; milli (m) = 10^-3; micro (u) = 10^-6; nano (n) = 10^-9
- Dimensional Analysis
- Dimensions must be the same on
both sides of the equals sign
- Because of that we
know time does not =
speed x distance
- mgh doesn't = 1/2mv^2
- Vectors
- Can either add, multiplied by
scalar, subtract, or resolved
into components
- An arrow indicates the
magnitude of the vector
- The direction of the arrow
indicates the direction of the vector
with respect to a given coordinate
system
- Vector Components
- Fx = Fcos(angle)
Fy = Fsin(angle)
- Chapter 2
- Aristotle's Mechanics
- celestial vs. terrestrial motion
- v=F/R (INCORRECT)
- What is Motion?
- Velocity and Speed
- Velocity is a vector, with
speed being its magnitude
- velocity=displacement/time
- instantaneous: velocity at a single point
in time (slope of position vs. time graph)
- Acceleration
- change in velocity/change in time
- Inertia
- Galileo's experiment with an inclined
surface set the cornerstone for the
principle of intertia
- Newton's Laws of Motion
- LAW #1: If the total force acting on an object is
zero, the object will maintain its velocity forever
- LAW #2: Total force acting on an object
is the sum of all of the forces acting on
that object
- F=ma
- 1N=1kgm/s^2
- LAW #3: When one object exerts a force on second object, the
second object exerts a force of the same magnitude and opposite
direction of the original force
- An object's resistance to motion
- Redefining Aristotles 'Laws'
- Reworking Theories is vital
- Motion with constant acceleration
- v +Vi +at
- Normal Forces and weight
- Apparent weight
- N = mg + ma
- Mass
- F gravity = -mg
- Free Body Diagrams
- recognize objects of interest
- Sketch!
- Identify Relationships
- Solve!
- Chapter 3
- AIr Drag
- Depend on Shape of Object
- Larger for Objects Moving at high speeds
- Bacterium
- Drag force large compared to weight
- Frictiojn
- Kinetic Friction
- Force against the force needed to continue moving an object on a surface
- Static Friction
- Force against the force needed to begin moving an object on a surface
- F=uN
- Free Fall
- Initial velocity equals zero under standard conditions
- a=gravity (9.8m/s^2)
- g is positive or negative depending on the direction of the vertical motion
- Tension
- T=mg+ma
- For a pulley system, Tension opposes mass and gravity
- Chapter 4
- Statics
- Translation equilibirum
- velocity and acceleration are both zero
- Ex) tight rope walker, tensions are in equilibrium
- Static Equilibrium and frictional Forces
- Example: for a car on a hill not to move normal force, mg, and friction must add to zero
- Projectile Motion
- motion of arrow, ball or rock when it is thrown
- Car rolling off a cliff. Car's velocity vector is always tangent to the tragectory
- the time the car takes to reach the ground is independent of the motion along x
- Reference Frames and Relative Velocity
- Inertial Reference Frame = Nonaccelerated Ref. Frame
- reference frame- observers choice of coordinate system
- Detecting Acceleration
- Newtons Laws
- Working with Frictional Force
- Pulleys and Cables
- Air Drag Continued
- Effect of Air drag on a bicycle