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Grades 7 and 9 Beginner About 15 min Version 1 Awaiting review Premium

Measuring average speed

Speed tells us how far something travels in a certain time. To find the average speed, measure the distance travelled with a measuring tape and the time taken with a stopwatch, then divide: average speed = distance ÷ time. Speed is measured in metres per second (m/s) or kilometres per hour (km/h); 1 m/s = 3.6 km/h. For something moving at a steady speed, doubling the distance doubles the time taken.

What you will learn

  • Measure distance and time and calculate average speed.
  • Show that, at a steady speed, distance travelled is proportional to time.
  • Convert speeds between m/s and km/h.

Before you start

  • Read a measuring tape and a stopwatch.

Materials

  • Chalk to mark the start and finish lines

Equipment

  • Measuring tape (100 m)
  • Stopwatch

Procedure

  1. Time the walker over a short, a medium and a long distance and record each run.
  2. Time the runner and the cyclist and compare their speeds.
  3. Time the bus and convert its speed into km/h.

How this simulation is simplified

  • Each mover keeps a steady speed for the whole run.
  • The stopwatch is started and stopped exactly on the lines.