       Objectives | Materials | Invitation To Learn | Lab Procedure | Closure  In this activity, students will learn about speed by calculating the average speed of several snowmobiles, and predicting which of them is the fastest. They will then watch a race to verify their calculations. Lesson Objectives: After completing this lesson, students will be able to: Use elapsed time and distance traveled to derive average speed. Recognize and use appropriate units for speed. Use average speed to predict final order of race completion. Background: Introduction: Everyday, most of us use some form of transportation to get somewhere. Whether that form is a car, bus, a bicycle, or our own two feet, understanding the concept of speed is important in today's world of schedules and time crunches. It is the concept that helps us figure out how long it will take us to go from one place to another. The race track is a place where speed is especially important. During a race, the snowmobiles in the track cover the distance in as little time as possible, so they can win the race. Science: Speed is the rate at which something moves and is defined by distance traveled divided by elapsed time. Preliminary Knowledge: Familiarity with units of measure for distance. Basic multiplication/division knowledge or capability to use a calculator.  Computer(s) with Internet connection (See our Technical Support page for minimum requirements and assistance.) Calculator Lab Notebook or Student Lab Packet - This is a printable version of the lab materials (instructions, tables, and questions). For the Introduction To Learn: racing objects (small cars, rolling balls, students, perhaps current racing stats or records set at school.)  Create a table on the chalkboard with 4 columns (students, distance, time, average speed). Ask 5 students, one at a time, to seperately walk in a straight line at whatever pace they like from one end of the classroom to the other. Have another student time (in seconds) how long it takes and report it to the class and record it in the table. Have another student (and a second to check his/her results) measure the distance walked. With the class calculate the average speed at which each student moved. Discuss with students what they think average speed means. Most will be familiar with miles per hour as it applies to their family car. If they can remember the unit miles per hour, they can remember the formula for speed: average speed = distance/time Compare the results and discuss what factors account for the variation in the results. If you were to make predictions on a race, would they want to collect any data before making their predictions?  Pre-Assessment: Directions for Teaching the Lab: Direct students to their student page. They should read the problem and be familiar with their task. Click through the data for each snowmobile. Allow students time to calculate speeds and make their predictions. Start the race! Have students record the order of the finish. Allow students time for analysis questions and conclusion.  Summary: Students should be able to calculate speed and estimate from time and distance measurements which moving object is fastest. Extension: Answer the questions posed on the first page of the computer lab. Students can measure the average speed at which they walk (about three miles an hour) and calculate the time it would take them to walk to the moon (a distance of 238,857 miles). (It would take about 80,000 hours, 3,300 days, or approximately 9 years.) They can do the same using their favorite snowmobile's average speed. They can also calculate using the speed of light (186,000 miles/second). Students could investigate the impact on society as greater speeds are attainable in transportation and communication. Look at how things have changed over a given time in history and predict changes in the future. Given the limit of 186,000 miles/second, how long would it take to communicate with someone who had reached Mars? How long would you expect to wait for a reply? Post-Assessment: A car traveled 100 miles in 1.2 hours. What average speed was it traveling? A car traveling 55 miles per hour travels for 2.5 hours. How far has it traveled? Two cars leave town at the same time. The first car travels 50 miles in 1 hour to reach its destination. The second car travels 90 miles in 2 hours to reach its destination. Without using your calculator, which car traveled faster?   