Click Grade 3: Forces at Work to access the lesson for the Grade 3—Force and Motion strand.
Gather the materials necessary to do the Elaborate, Part 1 activity. Read through the Teacher Note, Content Builder, and Advance Preparation in the lesson. Follow the directions in Teacher Instruction to do the activity.
Keep the following questions in mind as you work.
- How much force was used to push the box without wheels and axles? With wheels and axles?
- Which method of pushing was easier?
The spring scale may read 0 newtons used to move the box with wheels and axles. This does not mean that no force is being used. It simply means that so little force is being used that the spring scale is not powerful enough to detect it. You could always add heavier objects to the box to see if that would affect the force measurement.
Why did you repeat the experiment with three trials? Repeating trials improves the reliability of the results. For example, by doing three trials, a scientist can look at his or her results to see if the measurements all look similar. If one measurement is different from the other two, something may have gone wrong.
Did you demonstrate work in this activity? Work was only accomplished if the box ended in a different position from where it began.
View the video to review the activity.