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Going with the Flow:. A Vector’s Tale. Erik Scott. Highline CC. What is a vector?. Here are a few examples:. Why an arrow?. Compare: What does your eye do with each of the objects below?.
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Going with the Flow: A Vector’s Tale Erik Scott Highline CC
What is a vector? Here are a few examples:
Why an arrow? Compare: What does your eye do with each of the objects below? An arrow is the simplest stationary visual element we can use to convey motion in a specific direction.
Mathematicians and scientists aren’t the only ones who’ve recognized this fact. Artists are keenly aware of this, too.
My (formal) introduction to vectors: A river flows south at four meters per second, and a person wants to swim across. The person tries to swim straight ahead at three meters per second. What is the person’s actual heading? 3 m/s 4 m/s
Solution idea: Add vectors head-to-tail, then draw a final arrow connecting the tail of the first vector with the head of the last. That’s your direction. Calculations give you the speed. 3 m/s 4 m/s 5 m/s
Important features of the example: In this situation, everything moves at a constant speed. That’s what allows us to use only algebra and plane geometry. 4 m/s
A vector what? A “vector field.”
An activity for the kinesthetic learner.Also known as:“Pictures are great, but why should our eyes have all the fun?” • Stand up. (You are now a simple point.) • Point your left arm out towards a neighbor to your left. (Ta-da! You’ve been promoted to a vector.) • Take the paper ball with your right hand and pass it on with your left. (You’ve just become part of a vector field and created a flow line.)
A mathematical representation of our vector field. Website: http://math.la.asu.edu/~kawski/vfa2/index.html
Where do vector fields come from? • Repeated measurements in many locations. (Like checking currents at different places in a river.) • A theoretical understanding of how things change. (Building equations based on an understanding of the forces at work.)
Describing how things change:the domain of Calculus Vector fields are intimately connected to the mathematical objects called “differential equations.”
A second interpretation:(units have been adjusted for simplification)
And this can become as complex as you are prepared to handle: