Velocity Vectors Chapter 3.1-3.3

Quantities 1. Scalar 2. Vector Quantity described by magnitude only No direction Examples: mass, time, volume 2. Vector Quantity described by magnitude and direction Example: velocity

Vectors Arrows (vectors) are used to represent magnitude and direction of vector quantity 20 m/s East 10 m/s South

A velocity is sometimes the result of combining two or more velocities. Example 1: An airplane is flying north at 100 km/h relative to the surrounding air. Suppose there is a tailwind blowing north at a velocity of 20 km/h. What is the airplanes velocity relative to the ground?

Example 2: The same airplane turns around is now flying south at 100 km/h relative to the surrounding air. There is still a wind blowing north at a velocity of 20 km/h. What is the airplanes velocity relative to the ground?

Example 3: Consider an 80 km/h airplane flying north that is caught in a strong crosswind of 60 km/h blowing from west to east. What is the plane’s velocity? Resultant: the diagonal of the rectangle described by the two vectors

Components of Vectors A single vector can be changed into an equivalent set of two component vectors at right angles to each other. Determining the component vectors is called resolution. Vertical component Horizontal component

Example 4: An airplane’s resultant velocity is 150 km/h, if the crosswind relative to the plane is 90 km/h, what was the plane’s component velocity?

Example 5: Calculate the resultant velocity of an object with a horizontal component of 8 m/s and a vertical component of 6 m/s.