lecture 1: course introduction motion in one...

• Semester preview

• Motion along a straight line

• Position and displacement

Lecture 1: Course introduction

Motion in one dimension

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

Honda cog ad video

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

Course Orientation

Course website: http://web.mst.edu/~vojtaa/phys1145/index.html

A few tools:

• 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

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

Kinematics: Describing Motion

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 can be positive or negative ⟶ direction

If 𝑥𝑓 = 𝑥𝑖: Δ𝑥 = 0

Displacement is not the same as distance traveled!

Δ𝑥 = 𝑥𝑓 − 𝑥𝑖

* Change (upper case delta Δ) is the final

value of a quantity minus the initial value.