Newton's Third Law: Pair or Not a Pair

Eight illustrated cards, each describing two forces. Students decide: is this a real Newton's third-law pair, or not? The rule they apply is the heart of the standard - a third-law pair acts on two different objects (a swimmer and the water, a skate and the ice), while two forces on the same one object (gravity and a table both acting on a book) are balanced forces, not a pair. The cards mix objects at rest and objects moving, so students cannot sort by "is it moving?" A Sum It Up cloze locks in the rule.

What's Included

• 1 student page: 8 illustrated sort cards (4 pairs, 4 not-a-pairs) plus a Sum It Up fill-in with word bank
• 1 teacher key page with the answer and a one-line reason for every card, plus a Big Idea box that states the misconception fix
• Letter-size PDF, no prep

How It Helps You Teach

• Directly practices TEKS 6.7C: identify simultaneous force pairs that act between two objects
• Confronts the two classic mix-ups head on - that equal, opposite forces on one object are a "pair," and that the bigger object pushes harder
• Best used after the vocabulary and inference sheets, since it leans on the terms "force pair" and "reaction force"

Pair It With

This sheet is part of a four-activity Newton's Third Law set: Context Clues, Inferences, Science in the News (Olympic speed skating), and Science Sort. Check out our library for the other three and the full set.

Standards: TEKS 6.7C; NGSS MS-PS2-1. Part of the Daily Science series by Workybooks