Grade 3 · 4 lessons and a review

Forces and changes in motion

Build force diagrams, combine opposite forces, and explain motion with a stated model.

Before you begin

Choose by skill rather than age alone. Read with an adult when useful, revisit a lesson, or explore another grade.

Lesson 1 of 4

Use a simple force model to explain whether a cart starts moving.

Lesson 2 of 4

Find the direction and size of an unbalanced horizontal effect.

Lesson 3 of 4

Distinguish unchanged motion from being at rest.

Lesson 4 of 4

Revise a force conclusion when the model lists friction.

After the lessons, try 4 new review cases and a practical task. Each answer has an explanation and a link back to the related lesson.

Guest answers are temporary. Keep your own paper or document; this unit does not certify completion or record a school grade.