Balancing Forces Activity Kit Check Availability

Amplify Grade 3 Lesson 1.2 Balancing Forces

Students are introduced to their role as scientists and to the problem they will tackle in this unit—explaining how floating trains work. After seeing a short animated video of a floating train, students wonder what could make the train rise and what could make it fall back to the track. Students are then introduced to the more general Unit Question they will answer over the course of the unit: What can make an object move or not move? Students begin by investigating what makes an object start to move. Finding ways to move blocks, students learn that they cannot see the forces they make—forces are not something that can be seen—but students can see the effects of forces when a force causes an object at rest to move. Students point to these effects as evidence of forces. The purpose of this lesson is to engage students in firsthand experiences with forces and to provide them with practice in evidence-based thinking.

Materials included (16 groups worth):

• 2 Wood blocks with hooks
• 1 gallon plastic ziploc bag
• 1 rubberband
• 1 paperclip
• 1 domino
• 1 clothespin
• 1 index card

Also included:

• Masking Tape
• Scissors
• Marker