Forces and Motion
Aligned to 3-PS2 — Next Generation Science Standards.
What this lesson teaches
Forces can be balanced (no change in motion) or unbalanced (motion changes). Patterns in motion can be observed and predicted.
Worked example
In tug-of-war, if both teams pull equally the rope doesn't move (balanced); when one pulls harder, the rope moves toward them (unbalanced).
Practice questions
- What happens when forces are balanced?
- Give an example of an unbalanced force changing motion.
- Predict the motion if two equal forces push opposite ways.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Fuerzas y movimiento
Las fuerzas pueden estar equilibradas (sin cambio en el movimiento) o desequilibradas (el movimiento cambia). Los patrones en el movimiento se pueden observar y predecir.
Ejemplo: En un juego de jaló la cuerda, si los dos equipos jalan con la misma fuerza la cuerda no se mueve (equilibrado); cuando uno jala más fuerte, la cuerda se mueve hacia ese lado (desequilibrado).
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