Peoples Physics Concepts

http://www.ck12.org Chapter 4. Newton’s Laws

4.4 Free Body Diagrams

• Draw a free-body diagram and apply it to the real world.

Students will learn how to draw a free-body diagram and apply it to the real world.

Guidance

For every problem involving forces it is essential to draw a free body diagram (FBD) before proceeding to the

problem solving stage. The FBD allows one to visualize the situation and also to make sure all the forces are

accounted. In addition, a very solid understanding of the physics is gleaned and many questions can be answered

solely from the FBD.

Example 1

MEDIA

Click image to the left for use the URL below.

URL: http://www.ck12.org/flx/render/embeddedobject/383

Watch this Explanation

MEDIA

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URL: http://www.ck12.org/flx/render/embeddedobject/382

Explore More

1. Draw free body diagrams (FBDs) for all of the following objects involved (inbold) and label all the forces
   appropriately. Make sure the lengths of the vectors in your FBDs are proportional to the strength of the force:
   smaller forces get shorter arrows!
   a. Amanstands in an elevator that is accelerating upward at 2m/s^2.
   a. A boy is dragging asledat a constant speed. The boy is pulling the sled with a rope at a 30◦angle.