#214. vectors for beginning physics student

Science, level: Senior
Posted by Pat Carrow (pcarrow@kiwi.dep.anl.gov).
Community High School 94, West Chicago, IL
Materials Required: compasses (directional),protractors, graph paper, rulers, football field or playing board
Activity Time: 3 class periods
Concepts Taught: vectors, graphing

Day 1: Pacing
Mark off a long section (100 ft or so) and have the students measure their pace by counting steps over 1000 feet and then dividing by 1000.
Day 2: Use of compass
1. Instruct students on the use of a directional compass, sighting a landmark and pacing for distance
2. Direct students on how to read compass directions written on paper
3. Divide students into groups of 3 students, give each a compass, or use one compass and a 4th person
to act as "runner" to bring the compass back to the next student
4. Give the groups a set of vectors to "add", go to a football field to
give them plenty of room to do this - you will need to make up your vectors
before hand
5. Space your students far enough apart that they do not run into each other
6. The first student in a group reads the directions given, and moves to the
first vector location (200 ft at 200 degrees for eg)
7. The second student stands next to the first student (who is at their vector
location) and reads the next direction and follows the directions for the
second vector
8. The third student goes to where the second student is located and sights
the first student using the compass, makes a note
of the direction and then measures the distance
using pacing as the distance guide, and they all
record the distance and the direction the last
student had to travel.
Alternate plan if there is no football field or the weather rains
using the lab table or the floor, use markers and have the
students move markers the different locations on the floor
or very big lab table

Day 2 Graphing
1. Have students graph the vectors from the previous day, making
note of the direction and length of the final vector drawn
to scale
Day 3 Vector addition
If graphing calculators are available, show students how to translate
between rectangular and polar coordinates, and add vectors, compare
answers to the other two days work
If graphing calculators are not available, teach them some trig functions
and how to translate to polar coordinates and add the (x,y) coordinates
and compare the work from the previous two days.
Optional homework - map out the vectors that would describe
the circumnavigation of their home, graph it, add it