Middle school students are often familiar with the concept of speed from their everyday lives. At the same time, they might be confused about how to calculate speed, or how it differs from velocity. Knowing that velocity is simply speed in a specific direction can help them grasp this concept, and using speed and velocity activities can help reinforce it.
The Speed Olympics
One interactive way to have students practice calculating speed is to have them make their own mini-Olympic games in small groups. Let each group of students choose one activity that involves doing something "the fastest," such as running, pushing a ball with their noses or doing a set number of jumping jacks. Then have them try it out, with several members of the group participating and the remaining member timing them all. Encourage them to take accurate data on how long it took each person to complete the activity and to post their results on the board. Then ask students which activities they could use to calculate speed and which ones they could not. For example, they could calculate speed for the walking or pushing a ball activities, but not for the jumping jacks activity because no distance is involved. Instruct students to calculate the speed of these activities, and have them share their answers with the rest of the class.
On the Way to School
Instruct students to time themselves one morning on how long it takes them to get to school in the morning, whether they go by bus, by carpool or by foot. Then distribute maps of the area to them and have them use the scale of a map to calculate how far they travel in the morning. Some routes will be direct, whereas others -- such as bus routes -- will be roundabout. Encourage them to use these pieces of information to calculate the average speed at which they travel each morning. Discuss the idea that average speed is not constant, so they will be going at different speeds throughout their morning commutes. Then discuss whether they could measure velocity, even with a roundabout route that doesn't seem to have one direction.
Find Your Way on a Map
Divide students into groups, and give out a road map of a different area to each group. Have each group choose a starting place on the map and then write a list of instructions using only velocity and time to get from the starting point to a different point on the map. For example, one line of instructions might be "Go for 10 minutes, at a velocity of 60 miles an hour east." Instruct groups to swap maps and instructions with each other and to try to figure out what the other groups' destinations are.
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