Calculating Walking Speed from Distance and Time
About this lesson
Students time classmates walking a measured 5-metre path at different paces, then calculate each walker's speed in metres per second. They practise using speed = distance ÷ time and rearranging it to predict travel time. You need a metre stick, sticky notes and a stopwatch or clock with a second hand. It takes about 12 minutes.
- Grade
- 8
- Subject
- Science
- Time
- 12 min
- Prep
- 5 min
Objective
Students will calculate average speed in metres per second from measured distance and time, and rearrange the formula to predict how long a trip will take.
Prep
5 min: measure a 5 m path with a metre stick, mark both ends with sticky notes, and write speed = distance ÷ time on the board
Materials
- metre stick
- sticky notes
- stopwatch or clock with a second hand
- scrap paper and pencils
Steps
- Point to the formula on the board and explain that speed tells us how many metres something travels each second, so we divide distance by time.
- Ask three volunteers to walk the 5 m path one at a time: one slowly, one at a normal pace and one at a brisk walk. Time each walk aloud while students record the times on scrap paper.
- Have students calculate each walker's speed in m/s, rounded to one decimal place, then compare answers with a partner and fix any differences.
- Ask the class to use the normal walker's speed to predict how many seconds it would take that person to walk 100 m. Show them how to rearrange the formula to time = distance ÷ speed.
- Discuss why a 5 m measurement gives an average speed and what could make the timing inaccurate, such as reaction time or speeding up at the start.
Quick Check
Ask students to write the speed of someone who walks 12 m in 8 s (1.5 m/s) and hold it up on scrap paper.
Differentiation
Make it easier: Use a round time for each walker, such as 5 s or 10 s, so the division is simple.
Make it harder: Have students convert the brisk walker's speed from m/s to km/h by multiplying by 3.6, and discuss why the conversion works.
Good For
- Before lunch
- Review
- Supply teacher
- Brain break
