Learning Targets
- Describe where friction appears in a moving mechanism.
- Explain when friction is useful and when it causes performance problems.
- Recommend a design adjustment to improve reliability.
IED Unit 4 • Lesson 4.7
Friction, Force, and Mechanism Performance
Focus question: How does friction affect whether a mechanism works reliably?
Your lesson guide
Objective
Describe where friction appears in a moving mechanism. Explain when friction is useful and when it causes performance problems. Recommend a design adjustment to improve reliability.
Materials
For the online work: a browser and your engineering notebook. Follow the activity’s materials list for any physical build, and get teacher approval before using equipment.
Plan your time
Suggested work block: 45–60 minutes. Physical builds and projects may span several classes; follow your teacher’s schedule.
Mission Briefing
Today’s Plan
Use this page with the lesson presentation, your engineering notebook, and the tools or evidence assigned for Investigate Friction and Mechanism Performance.
Success Looks Like
You can explain how friction can help or hurt mechanism performance and propose a design adjustment.
LaunchLearnApplyCheckSubmit
Opening Prompt
How does friction affect whether a mechanism works reliably?
Connect your response to the decision, evidence, or quality standard required for Investigate Friction and Mechanism Performance.
Reveal: useful engineering move
This lesson is ready to move forward when the evidence meets this standard: The conclusion identifies the tested condition and does not confuse friction with an unrelated design change.
Core Skill
What We Are Practicing
Friction can provide grip, resistance, or unwanted energy loss.
Mechanism performance depends on contact surfaces, alignment, force, and material choice.
A friction problem should be diagnosed before parts are redesigned.
Your Task
Investigate Friction and Mechanism Performance
Compare mechanism performance under different contact, load, or lubrication conditions using a controlled test.
- Define the performance measure to observe.
- Change only the assigned friction-related condition.
- Record force, travel, time, or qualitative behavior consistently.
- Explain how friction helped or harmed performance.
Quality check: The conclusion identifies the tested condition and does not confuse friction with an unrelated design change.
Lesson Interactive
Estimate Friction in a Sliding Guide
Calculate friction force and decide whether the design should increase or reduce it.
Estimated friction force
Use Ffriction = μN.
Set the given test values and choose a response that supports smooth sliding motion.
What You Will Submit
Friction Test Evidence
Submission standard: The conclusion identifies the tested condition and does not confuse friction with an unrelated design change.
Resources
Lesson Resources
Lesson 4.7 PowerPoint
Use the lesson slides for guided practice, interactive checks, and the exit ticket.
Introduction to Engineering Design
Return to the IED course hub for units, resources, certifications, and current course information.
Build your lesson report
Checkpoint: is your evidence ready?
- Check calculations, units, labels, and measurements against the activity requirements.
- Record what actually happened, including unexpected results.
- Explain what you changed and why; attach required drawings, photos, CAD, or code in your classroom assignment.
Submit the evidence specified in the activity and your classroom assignment. The report below collects your notes, calculations, observations, and reflections; attach any required drawings, photos, CAD, or code separately.
A PDF download is not a submission. Review it, then upload it and any required attachments through your classroom assignment system.