Student Conception: Average speed and instantaneous speed

[Matt Anthes-Washburn]

Student Conception: Average speed and instantaneous speed
Students may fail to recognize that each tick represents a unit of time and the distance between ticks on the tape represents how far the object goes between ticks.

Identifiers
If students have a hard time telling whether the tape shows a high speed, a low speed, or whether the speed is increasing or decreasing, this may indicate a failure to relate the characteristics of the ticker tape to the physical motion.

Formative Assessment Question
Ask students if moving faster will result in the ticks on the tape getting closer together or farther apart.

Interventions
In the For You To Do, students are asked to predict the pattern they will see on the ticker tape for particular motions. Students use the ticker tape to make speed vs. time histograms. Students can compare their predictions in the formative assessment with the experimental results of using the ticker tape timer.