Lecture2

Lecture2 - Physics 2A Lecture 2: Jan 9, 2008 Vivek Sharma...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
Physics 2A Lecture 2: Jan 9, 2008 Vivek Sharma UCSD Physics
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Reading Assignments For This Week Self-Study “How to Succeed in Physics by Really Trying”, & Using Your Textbook” & Chapter 1 : Sections 1.1-1.6 Second Quiz on Tuesday 15th, Covers Ch 1 Start reading NOW !
Background image of page 2
Today : Start Gathering Tools • Nature of Physics • Idealized Models • Standard & Units • Measurement Error • Order of magnitude • Significant figures • Scalars & Vectors
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Nature of Physics • Physics is experiment driven science • Observe phenomena , find patterns & principles (physical theory) that relate and explain diverse observed phenomena • Every physical theory has a range of validity outside which it is not applicable Æ CM
Background image of page 4
Models in Physics • Model is a simplified version of a physical system that would be too complicated to analyze in full detail • In a model, we overlook the minor effects to concentrate on the most important feature of the system it describes, e.g. analyzing motion of a baseball thrown in air • The predictions based on a model are only as good as the features present in the model • Will use models of phenomena throughout the course to learn about its essential features
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
An Example of Idealization/Modeling
Background image of page 6
Unit of Physical Quantities • Physics is an experimental science, experiments require measurements • A number used to describe a physical phenomenon quantitatively are called physical quantities . e.g. your height and weight • When measuring a quantity, we compare it with some reference standard. Such a standard defines a unit of the quantity – e.g: SI Units – units of measurements must be calibrated: exactly the same in all parts of the universe ! Kilogram (kg) Second (s) Meter (m) Mass Time Length
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Describing Physical Quantities •Sca la r s Æ Quantities such as time, temperature, mass, speed can be described by just one number with an appropriate unit –math is simple: 2kg +3kg = 5kg (always!) • Vectors Æ Quantities with direction associated with them such as those quantifying motion (displacement, velocity) –needs a magnitude (how large or small) –needs a pointing direction (which way?) –math for these objects is more complicated
Background image of page 8
• Describes net change in position of an object • An example of a displacement vector • Example of same displacement vector but with a different path • Apologies to Robert Frost, both paths taken arrive at the same point same magnitude, directions, although paths very different The Displacement Vector V V
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The Zero Vector
Background image of page 10
Equal, Parallel & Anti Parallel Vectors
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 08/23/2008 for the course PHYS 2A taught by Professor Hicks during the Winter '07 term at UCSD.

Page1 / 39

Lecture2 - Physics 2A Lecture 2: Jan 9, 2008 Vivek Sharma...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online