11-27-07 - Intro To VectorsPresentation Transcript
VECTORS Chapter 4.1
Scalar or Vector?
What am I, a scalar or vector quantity?
Scalar – only magnitude
Vector – magnitude AND direction
Velocity, Force, Acceleration, Displacement
5 mph north
15 m/s northwest
1.2 N west
Vectors Vectors have magnitude and direction. They add or subtract depending on their directions. Parallel vectors are pretty simple: 50 N 50 N = 100 N + 50 N 50 N = + 0 N What if the vectors are NOT parallel: Example: What if I walked 16 km East and 12 km North The result is a NET movement of 20 km Northeast 16 km East 12 km North 20 km Northeast Component Vectors Resultant Vector
To work with vectors, it is important to know how to perform vector addition both graphically and analytically.
Graphically – draw vectors to scale and measure
Analytically – use formulas
When 2 or more vectors act on an object, they act independently of one another.
Their combined action will result in a net effect.
The purpose of vector addition is to determine the net figure and direction.
The net figure is called the “resultant.”
The best way to determine the measurement of a resultant is mathematically, but sometimes it is necessary to draw the vectors to scale and measure the resultant with a ruler and protractor.
Let’s look at an example…
Let’s examine a picture of a boat crossing a river.
The boat is moving due east at 8.0 m/s, and the river is flowing due south at 5.0 m/s.