Zusammenfassung der Ressource
Physics Exam 1
Group 5B
- Chapter 2:Motion, Forces
and Newton's Laws
- Position & Displacement
- Position: location relative to the
origin or reference point
Displacement: change in object's
position (shortest distance)
- displacement=final-initial
- Speed & Velocity
- Velocity: vector that
measures how fast AND
direction it goes
- average velocity= displacement/time
- velocity vs time graphs
- Average Speed= distance traveled/time of trip
- distance vs. time graphs
- Acceleration
- nonzero acceleration
changes an object's state
of motion
- average acceleration= velocity/ time
- Newton's First Law
- inertia
- object in motion will stay in
motion while an object at rest will
stay at rest
- inertia: measure of an object's resistance to
change in its motion; depends on its mass (SI unit is kg)
- Newton's Second Law
- link between
motion and forces
- multiple forces act on an object
at one time; use newtons (N)as
the SI unit
- many applications
- force= mass*acceleration
- Newton's Third Law
- where forces come from
- Chapter 1: Introduction
- Problem Solving Techniques
- KUDOS method
- K=known; U=unknown;
D=definition(formula);
O=output(calculations);
S=substantiation(check it)
- Types of problems
- 1. Quantitative Problems 2. Concept Checks
3. Reasoning & Relationship problems
(Identify what important might be "missing"
- Scientific Notation
& Significant Figures
- Shorthand of writing
very large and/or small
numbers
- Significant Figures
- 1. Nonzero digits ARE
significant 2. Final ending
zeros written to the right of
the decimal ARE significant
3. Decimals that are
placeholders are NOT
significant 4. Zeros written
between digits ARE
significant
- Round numbers at the VERY end
- Units Conversions
& Dimensions
- Dimensions: basic types of quantites
that can be measured or computed
- Unit: Standard amount of a dimensional quantity
- EXAMPLES: kg,m,s
- EXAMPLES: Length, Time, Mass,
Electric Current,
Temperature
- Dimensional Analysis:
used to check problems
- Use: L for length, T for time, M for mass
- Vectors
- Written as an arrow and length mean
magnitude and direction means direction
it would be on a coordinate system
- use trig. to find the
sides and/or angle
(cosine and sine)
- to add vectors, tip-to-tail so A+B=C
- Chapter 3:Forces and
Motion in One Dimesions
- Constant Acceleration
(Equations of Motion)
- velocity final x=velocity
initial x+ (acceleration*time)
- x= (velocity initial x* time)+
1/2*acceleration*time
squared
- velocity final squared= velocity initial
squared +2*acceleration*x
- force= mass*acceleration
- Normal Forces
& Weight
- normal force; perpendicular to
plane of contact
- weight is mass*gravity
- Free Body Diagram
- shows all forces acting on
each object in a problem
- Free Fall (1D motion)
- under the influence of gravity
(+ or- 9.8 meters per second
squared)
- velocity final= velocity initial + acceleration*time
- x= velocity initial*time+ 1/2*acceleration*time squared
- velocity finial squared= velocity initial squared+ 2*acceleration*x
- Newton's Second Law
Applications
(Transmitting forces)
- apparent weight
- a<0; N=mg+ma (apparent weight
is greater than true weight)
(downward motion)
- a<0; N=mg-ma (apparent weight is less than
true weight) (upward motion)
- a>0; N=mg+ma (apparent weight is
greater than true weight)(upward
motion)
- a>0; N=mg-ma (apparent weight is less
than true weight) (downward motion)
- friction
- kinetic friction= force
kinetic* normal force=
mass*acceleration
- static friction= force static* normal force
- no units
- tension
- ideal tension is zero
- use free body
diagram to find
tension