The motion
Introductory activities
We recall the students’ ideas and experiences on the motion in the everyday life, starting from questions such as:
- How can we describe a walk, a run…? ( concept of trajectory, pace…)
- What quantities are involved? (length, time, velocity…)
- What does it mean “I’m moving” or “I’m still” (necessity of a reference system; I can be still related to the ground, but I’m moving related to the sun…)
Pupils walk along a defined straight trajectory
They:
- measure the distance walked, the time taken for walking along the whole distance, the time taken for walking along single distance fractions
- calculate the mean speed
- draw the distance vs. time graph (Excel)
Amin's walk
Time (s) |
Distance(m) |
Distance/time |
2,3 |
3 |
1,3 |
4,1 |
6 |
1,5 |
6,1 |
9 |
1,5 |
8,4 |
12 |
1,4 |
9,6 |
15 |
1,6 |
11,8 |
18 |
1,5 |
Walk with a motion detector
Pupils move in front of a motion detector and observe in real time the graph generated by their own motion. They soon discover that how one moves affects the shape of the line which the computer draws.
Pupils love to be engaged in competitions such us “Who draws on the screen the line that better fit the given graph?” They are stimulated to watch each other and to learn from the others’ errors, in order to make accurate predictions about the effects of their motion on the graph .
The comparison between the given line and the graph generated while moving is possible because as one moves, the graph describing his/her motion is generated alongside the given graph.
They soon discover that:
- to make the computer draw a horizontal line, they should stand still
- to make the computer draw a steeper line, the walker should speed up
- to make the computer draw a flattening line, the walker should slow down
- to make the computer draw a line that changes direction (from up to down or down to up), the walker should change direction
- to make the computer draw a wavy line, the walker should move back and forth many times
- This is a motivating and meaningful way to teach how to read and interpret a graph.
Pupils soon discover that:
- to make the computer draw a horizontal line, the walker should stand still
- to make the computer draw a steeper line, the walker should speed up
- to make the computer draw a flattening line, the walker should slow down
- to make the computer draw a line that changes direction (from up to down or down to up), the walker should change direction
- to make the computer draw a wavy line, the walker should move back and forth many times
This is a motivating and meaningful way to teach how to read and interpret a graph.
