What is a Vector A vector is a











































































- Slides: 75
What is a Vector? • A vector is a mathematical object which describes magnitude and direction • We frequently use vectors when solving problems in Physics Example: • Change in position (displacement) • Velocity
Notation
Direction • In one dimensional space, we may use a sign to denote the vector’s direction • For this sign to have any meaning, we must define the positive and negative directions N • For Example Up Down W E S
Displacement
Displacement
Displacement
Displacement
Displacement meters
Distance vs. Displacement does not depend on the path taken, only the initial and final positions All three paths have the same displacement
Distance vs. Displacement • Distance is the total length of the path taken • Distance does depend on the path • An odometer measures distance Which path has the shortest distance?
Distance vs. Displacement If a student drives 4 miles from home to school, and, at the end of the day, 4 miles from school back home. What was his displacement? What was the total distance traveled?
Distance vs. Displacement What was his displacement? What was the total distance traveled? meters
Distance vs. Displacement What was his displacement? What was the total distance traveled? meters
Velocity
Velocity
Velocity vs. Speed
Velocity - Example
Velocity - Example Your third period classroom is 150 m away from your second period classroom. You have four minutes between classes. Assuming you walk in a direct path, at this same speed, will you make it to class on time?
Velocity - Example
Velocity - Example
Velocity - Example
Velocity - Example
Velocity - Example West 2 East 4 8 km
Velocity - Example West 2 East 4 8 km
Velocity - Example West 2 East 4 8 km
Velocity - Example West 2 East 4 8 km
Acceleration
Acceleration
Acceleration Even if an object is traveling at a constant speed, if the direction of the motion changes, the object is accelerating.
Acceleration vs. Deceleration • Deceleration – speed is decreasing • Deceleration occurs when the acceleration opposes the motion • Deceleration is not the same as negative acceleration
Acceleration vs. Deceleration Example: A falling apple experiences a negative acceleration because it is falling downward. Up However, the apple is not decelerating. Down
Acceleration – Example
Acceleration – Example
Constant Acceleration
Constant Acceleration - Example
Constant Acceleration
Constant Acceleration •
Constant Acceleration
Free Fallin’
Free-Fall Example
Free-Fall Symmetry • Free-fall problems exhibit a natural symmetry
Free-Fall Symmetry
Free-Fall Symmetry How long does it take for the object to return to its initial height?
Free-Fall Example
Free-Fall Example
Free-Fall Example
Graphical Analysis
Graphical Analysis – Constant Velocity
Instantaneous Velocity
Graphical Analysis – Changing Velocity
Graphical Analysis – Instantaneous Velocity
Graphical Analysis – Instantaneous Velocity
Graphical Analysis – Constant Acceleration
Graphical Analysis
Graphical Analysis
Graphical Analysis Recall that the product of two values can be visualized as the area of a rectangle.
Graphical Analysis
Graphical Analysis
Velocity Graphical Analysis Time
Velocity Graphical Analysis Time
Velocity Graphical Analysis Time
Graphical Analysis
Graphical Analysis
Graphical Analysis
Graphical Analysis
Graphical Analysis
Graphical Analysis