Measurement of Time and Motion: common misconceptions

If your child says… “Modern clocks don't need anything to repeat.”

Ask together

Would invisible repeats stop being useful for counting time?

What’s true

Repeats can happen without being visible.

If your child says… “Reaching the other end completes a swing.”

Ask together

Has it returned to where you released it?

What’s true

Reaching the other end completes only half.

If your child says… “I'll write sec.”

Ask together

Which symbol matches our SI unit?

What’s true

Use s for seconds.

If your child says… “The longer time means faster.”

Ask together

Which trip finished sooner?

What’s true

Taking less time over that distance means faster.

If your child says… “I'll divide seconds by metres.”

Ask together

Does m/s put metres or seconds above the division line?

What’s true

Divide distance by time.

If your child says… “I'll divide speed by time for distance.”

Ask together

Would dividing by a longer time give more distance?

What’s true

Longer travel at unchanged speed covers more distance.

If your child says… “Straight always means uniform.”

Ask together

Did the ball keep the same speed as it approached the top?

What’s true

Changing speed makes this straight motion non-uniform.