All physics quantities fall into one of twocategories:Scalar – a quantity that can be described with asingle number (size, magnitude). Ex. I drove 15 miles. This is the quantity known as distance
Vector – a quantity that includes a number and adirection. Ex – I drove 10 miles south. This quantity is known as displacementDisplacement can be defined two ways 1) distance traveled in a particular direction 2) final location relative to a starting point
Which person traveled the greatest distance?Which person had the greatest displacement?
Vectors are represented by an arrow - the length represents the size or magnitude - the angle represents the direction
Vector AdditionResultant: the term given for the final sum vector whenadding 2 or more vectors together Question: 4 cm + 5 cm = ? WRONG!!! 4 cm north + 5 cm north = ? 9 cm north 4 cm north + 5 cm south = ? 1 cm south
I walk 3 blocks south, 4 blocks east and3 blocks north.a)What is my distance covered?b)What is my displacement?
How does the displacement of a moving objectcompare to its distance covered? Displacement <= distance
A duck walks 60 m north and then 40 meast. Using a scale of 1 cm = 10 m, drawthe displacement vectors of the duck.What is the resultant displacement?What is the angle between the resultantand north?
Adding vectors – the parallelogram method also called the Tip to Tail Method
Add two vectors:100 mi east50 mi at 45o north of eastFind the length and direction of theresultant using a ruler and protractor.