Physics Lecture 3 PDF

62 Content of the Course ❖ Chapter 1: Physical Quantity, Units and Dimensions (1weeks) ❖ Chapter 2: Motion in one Dimension and (2 week) ❖ Chapter 3: Vector Analysis (2 week) ❖ Chapter 4: Waves, Oscillations and Sound (2 weeks) ❖ Chapter 5: ligh...

62 Content of the Course ❖ Chapter 1: Physical Quantity, Units and Dimensions (1weeks) ❖ Chapter 2: Motion in one Dimension and (2 week) ❖ Chapter 3: Vector Analysis (2 week) ❖ Chapter 4: Waves, Oscillations and Sound (2 weeks) ❖ Chapter 5: light lenses and mirrors (2 weeks) ❖ Chapter 6: Heat and Thermodynamics (2 weeks) ❖ Chapter 7: Electricity & Magnetism (2 weeks) Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Chapter 3 63 Vectors  Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Vectors 64  Topics 3.1 Coordinate Systems 3.2 Vector and Scalar Quantities 3.3 Some Properties of Vectors Equality Addition Commutative associative Negative of a Vector Subtracting Multiplying a Vector by a Scalar 3.4 Components of a Vector and Unit Vectors Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Vectors 65  Physical quantities that have both magnitude and direction are represented by vectors. 3.1 Coordinate systems a) Cartesian (rectangular) coordinate system Any point P is labeled with the coordinates (x, y) b) Plane polar coordinates Any point P is labeled with the coordinates (r, θ) Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Relations between both systems 66 Ex.3.1: The Cartesian coordinates of a point in the x- y plane are (-3.50, -2.50) m. Find its polar coordinates ? Note that: the point lies in the third quadrant Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  3.2 Vector and Scalar Quantities 67  A scalar quantity has only magnitude and no direction. Examples: Temperature, mass, time interval, pressure, ….. etc.  A vector quantity has both magnitude and direction. Examples: Displacement, velocity acceleration, force, …..etc. Vector’s notations Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Displacement Vector 68 A particle is moved from point A to point B The magnitude of the displacement vector is the shortest distance between the end points (A and B) of the displacement vector regardless of the trajectory. Note That: The distance travelled is different from the magnitude of the displacement vector. Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  3.3 Some Properties of Vectors 69 Equality of two vectors 𝐴Ԧ 𝐵 𝐶Ԧ Addition: Two vectors Parallelogram method Triangle method 𝐷 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Addition: More than two vectors 70 Commutative Law Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Associative law 71 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Subtraction of vectors 72 Multiplication of a vector by a scalar Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 Ex.3.2 A car travels 20.0 km due north and then 35.0 km in a direction 60.0° west of north, as shown below. Find the magnitude and direction of the car’s resultant displacement? 73 Using the law of cosines from trigonometry. Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  3.4 Components of a Vector and Unit Vectors 74  Components of a vector Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Unit Vectors 75  Vector quantities often are expressed in terms of unit vectors Representing a vector using unit vectors Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Sum of vectors using components 76 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Vectors in three-dimensions 77 Vectors components Vectors summations Similar to the two-dimensions case, we can write Ex.3.3: Find the sum of two vectors A and B lying in the x-y plane and given by: Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 78 Find the magnitude and direction of R ? Why ? Answer : The vector lies in the fourth quadrant. Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Ex.3.4 The resultant displacements 79 a) Find the components of the resultant displacement and its magnitude. The components are: (b) Find the magnitude of R? Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 Example 3.5 Taking a Hike A hiker begins a trip by first walking 25.0 km southeast from her car. She stops and sets up her tent for the night. On the second day, she walks 40.0 km in a direction 60.0° north of east. 80 (A) Determine the components of the hiker’s displacement for each day? (b) Determine the resultant displacement? (C) Find the resultant displacement magnitude and direction???????? Engineering Physics I Prof. Dr. E. F. Abo Zeid 10/5/2024  Quick Quizzes 81 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 82 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  Answer to Quick Quizzes 83 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 84 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024  HW- 3 Serway Version 8 Problems 5, 15, 31, 37 and 43. 85 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 86 HW- 3 Solutions Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 87 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 88 Physics Prof. Dr. E. F. Abo Zeid 10/5/2024 89 Thanks for your attention Physics Prof. Dr. E. F. Abo Zeid 10/5/2024