POE Unit 1 • Lesson 1.8

Work, Power, and Efficiency in Mechanical Systems

Use data to calculate work, power, and efficiency for a mechanical or electromechanical system.

Lesson Snapshot

Student Objective

I can calculate work, power, and efficiency using measured input and output data from a mechanical system.

Main Activity

Measure force, distance, time, or load movement in a VEX or classroom mechanism and calculate performance values.

Deliverable

Work, power, and efficiency data sheet

Tools / Materials

VEX mechanism or test setup, spring scale, stopwatch, ruler, calculator, notebook

1ProblemUnderstand the challenge and why it matters.

A mechanism may work, but it may waste energy through friction, slipping, flexing, or poor alignment. Efficiency calculations help engineers compare performance and identify improvement opportunities.

2ConceptLearn the engineering idea or skill.

Power describes how quickly work is done. Efficiency compares useful output work or power to the input work or power supplied to the system.

3ApplyUse the skill in a guided task.

Collect measurements from a mechanism that lifts, pulls, or moves a load. Calculate work, power, and efficiency, then identify one reason the system did not reach ideal performance.

4DocumentRecord your evidence and decisions.

Record data, calculations, units, and a conclusion that explains how friction, alignment, gearing, or structure affected efficiency.

5ReviewCheck quality and identify your next step.

Your conclusion should connect the numbers to the physical system. Do not just report efficiency; explain what caused it.

Lesson Resources

Use these files and shared website resources when they support today’s work.

Engineering Graph Paper

Use for sketches, layouts, calculations, systems diagrams, and test planning.

Open Resource

Measurement Data Sheet

Record repeated trials, measurements, calculations, and observations.

Open Resource