Choose the object
Identify Earth, touching surfaces, taut ropes, and other objects that interact with the selected object. Keep forces on other objects on their own diagrams.
AP Physics 1 · Unit 2, Part 1 · Forces
Free-Body Diagrams Practice Problems
Draw the forces acting on one chosen object. Practice 18 situations involving surfaces, ropes, friction, inclined planes, falling objects, and projectiles.
18 questions18 diagram-drawing questions
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What you’ll practice
Build a force diagram from the interactions
Draw forces with meaningful directions
Add weight, normal force, tension, friction, and applied forces. Use each surface and rope’s orientation to choose the arrow direction.
Compare relative arrow lengths
Use rest, steady motion, and acceleration to decide which forces balance. Handle angled pulls, two ropes, and multiple supporting contacts.
A question from this set
A tablet on a desk
Draw the forces on a tablet resting on a level desk. Nothing pushes or pulls it horizontally.
Draw and label your force arrows in the practice set. Check the force types, directions, and relative lengths.
Try it in the practice setKey ideas
Every force arrow needs another interacting object
Support depends on the contact
A desk exerts a normal force; a taut rope exerts tension. A ramp’s normal force points perpendicular to its surface, while weight stays vertical.
Draw full interaction forces
Components help with calculations, but a free-body diagram should not count an original force and its components as separate interactions. Use relative lengths to show the required balance.
See the physics
Draw first, then compare with the physical scene
Use the diagram editor to add and label arrows. Check their types, directions, and qualitative lengths, then run the scene to compare your diagram with the object’s motion and force arrows.
Use the hints to reconsider interactions and directions. Worked solutions show the force diagrams and explain their balance. Your progress saves in this browser.
Ready for free-body diagrams?
Draw your first force diagram and check the interactions.