3-PS2-1: Investigate balanced and unbalanced forces.

Official text

Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object.

What it means for your child

Your child plans and carries out tests to show that balanced forces do not change an object's motion and unbalanced forces make it start, stop, speed up, slow down or change direction.

Try it at home

1. Play tug-of-war with a towel. When nobody moves, the forces are balanced. When one side wins, they are unbalanced.
2. Roll a ball and push it gently from the side. Ask your child to describe how its motion changed.
3. Stack books on a toy car and push it with the same push as an empty car. Talk about what changed.