Lecture 1: Course introduction
Motion in one dimension
• Semester preview
• Motion along a straight line
• Position and displacement
What is physics?
Most fundamental of sciences
Behavior and structure of matter
Galaxy NGC 300, seven million lighters away, constellation Sculptor.
Courtesy of NASA.
High energy proton collision in the LHC. © CERN
Why study physics?
Required for major:
• Organisms and their components must obey
the underlying laws of physics
• Examples
• Physics can help explain biological processes
• Simulation: DNA molecule through cell
membrane
Find out how the world works
Because it is FUN
Demonstrations
Topic overview
Fall semester 1145: Mechanics
• Motion of objects
• Forces, friction, circular motion
• Energy and momentum
• Motion of planets
• Rotational motion
• Fluids
• Oscillations and waves
Spring semester 2145: Electricity and magnetism
• Charges, circuits, magnets, light
Honda cog ad video
Course Orientation
Course website: http://web.mst.edu/~vojtaa/phys1145/index.html
A few tools:
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SI system of units (metric system): kg, m, s
Unit conversions
Scientific notation
Prefixes: micro, milli, centi, kilo… (Table 1.2)
Estimates
Please review on your own as needed.
See Ch. 1, Sec. 1.4
Basic math skills required in this course
• Linear equations, systems of linear equations
• Quadratic equations
• Basic trigonometry: SOHCAHTOA, Pythagoras
Trigonometry is a prerequisite for this course.
If you got permission to take the course without having taken
a formal trigonometry course, make sure to review
Homework # 1 will help you review
math skills
• Vectors (will be covered next week)
Motion in one Dimension
Kinematics: Describing Motion
Particle model or “point mass” → only translation
Things to know about a moving object:
Where is it? ➔ Position
How fast is it moving and in which direction?
➔ Velocity
How do speed and direction of motion change?
➔ Acceleration
Position
• In reference to some coordinate system
• numerical value x
• x(t) is location of particle as a function of time
• Initial position: xi = x(ti) *
* Particle does not have to start at the origin
Discuss: textbook, Table 2.1, Figures 2.2 and 2.4
Displacement
Displacement = Change in position: *
Δ𝑥 = 𝑥𝑓 − 𝑥𝑖
* Change (upper case delta Δ) is the final
value of a quantity minus the initial value.
Δ𝑥 can be positive or negative ⟶ direction
If 𝑥𝑓 = 𝑥𝑖 : Δ𝑥 = 0
Displacement is not the same as distance traveled!