1-Coordinate system and Vectors.pdf

Coordinate system and Vectors Electromagnetics for medical physics Second year ‫الكهرومغناطيسية للفيزياء الطبية المستوى الثاني‬ The first lecture ‫المحاضرة االولى‬ Dr. Faten Monjed Hussein 1 Scalar: A physical quantity th...

Coordinate system and Vectors Electromagnetics for medical physics Second year ‫الكهرومغناطيسية للفيزياء الطبية المستوى الثاني‬ The first lecture ‫المحاضرة االولى‬ Dr. Faten Monjed Hussein 1 Scalar: A physical quantity that can be completely described by its magnitude is called a scalar. For example: mass, time, temperature, work, and electric charge. Vector: A physical quantity that having a magnitude as well as a direction. For example: force, velocity, torque, acceleration, and electric field. A vector quantity is graphically depicted by a line segment equal to its magnitude according to a convenient scale, and the direction is indicated by means of an arrow, as shown in Figure 1, where 𝑅⃗ represents a vector directed from point 0 toward point p. Figure 1 Graphical representation of a vector Important note: - ⃗Avector of magnitude zero is called a null vector or a zero vector. - ⃗Avector of unit magnitude (length) is called a unit vector. We can always represent a vector in terms of its unit vector. For example, vector A can be written as ⃗ and a⃑A where 𝐴 or |𝐴| are the magnitude of A ⃗ is the unit vector in the same direction of A such that 2 If ⃗A and B are two vectors, then Magnitude of vector 𝐴 𝑖𝑠 |𝐴| 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Coordinate's systems Coordinates systems are often used to specify the position of a point, but they may also be used to specify the position of more complex figures such as lines, planes, circles or spheres. The choice of the coordinates system is based on the problem one is studying. 19 Cartesian system Cylindrical system 20 Relation between cartesian and cylindrical Spherical System 21 Relation between cartesian and Spherical system 22 23 24 25 26