Upload
sophie-perkins
View
218
Download
2
Tags:
Embed Size (px)
Citation preview
1
Tuesday, Sept. 10: 17:20 – 19:10Wednesday, Sept. 10: 17:20 – 19:10Thursday, Sept. 10: 17:20 – 19:10
Building 6, Room 125(For students of Dr. Al Ramadan)
Evening Classes (Chap. 1 and 2)
2
Coordinate systems, vectors and scalars
Lecture 05 (Chap. 3)
General Physics (PHYS101)
www.cmt.ua.ac.be/golib/PHYS101
3
Coordinate Systems
•Coordinate systems are used to describe the position of an object in space
•Coordinate system (frame) consists of:✦ a fixed reference point called the origin✦ specific axes with scales and labels✦ instructions on how to label a point relative to the origin and the axes
0 x1 2 3 4 5 (cm)
6
Polar Coordinate Systems
•the origin and the reference line
•point is distance r from the origin in the direction of angle , from the reference line
•points are labeled (r, )
7
Coordinate conversions
•from polar coordinate to Cartesian coordinate
•from Cartesian coordinate to polar coordinate
9
Trigonometric functionsExample: how high is the building?
Known: angle and one sideFind: another side
height=dist. tan =(tan 39.0o)(46.0 m)=37.3 m
10
Scalar and Vector Quantities
•Scalar quantities are completely described by magnitude only (temperature, mass, time, length ...)•Vector quantities need both magnitude (size) and direction to completely describe them (force, displacement, velocity ...)
•Represented by an arrow, the length of the arrow is proportional to the magnitude of the vector
•Head of the arrow represents the direction
x
11
Vector Notation
•When handwritten, use an arrow:
•When printed, will be in bold print:
•A normal letter is used for its magnitude:
12
Properties of Vectors
• Two vectors are equal if they have the same
magnitude and the same direction
• Two vectors are negative if they have the same
magnitude but are 180o apart (opposite direction)
•The resultant vector is the sum of a given set of
vectors
13
Properties of Vectors
•Any vector can be moved parallel to itself without
being affected
y
x
•Rotation is not allowed!!!
14
Division and multiplication by a Scalar
•The result of the multiplication and division is a
vector•The magnitude of the vector is multiplied or
divided by the scalar.
•If the scalar is positive, the direction of the result
vector if the same as of the original vector
•If the scalar is negative, the direction of the
result vector if the opposite as of the original
vector