Are You Working Lesson Plan Are You Working? Or Just Moving Stuff?
Physics & Energy: The Scientific Definition of Work
7th Grade Science
45 Minute Lesson
Why This Matters
Understanding the scientific definition of work is fundamental to grasping energy transfer and other key physics concepts. This lesson clarifies common misconceptions and provides a solid basis for future science learning.
Teacher Prep
• Review lesson plan and slide deck visuals.
• Prepare whiteboard or projector for slides.
• Print and cut Work or Not Work? cards (1 set per group).
• Clear space for desk-pushing demonstration.
Materials
Projector & Whiteboard
Markers/Pens
Student Notebooks
Are You Doing Work? SlidesWork or Not Work? Cards
01 Engage & Inquire: What is Work? 10 MIN
Hook (2 min): Ask students: "What does 'work' mean to you?" Write responses on the board (e.g., homework, chores, a job, effort).
Think-Pair-Share (3 min): Discuss: "Is lifting a heavy box 'work'? Is pushing against a wall 'work'? Why or why not?"
Definition (5 min): Introduce the concept: Work is done when a force causes an object to move a distance in the direction of the force. Use Slides 1-3 .
02 Explore & Discover: Force & Distance 15 MIN
Demonstration (5 min):
Formula (5 min): Introduce \(W = F \times d\). Explain units: Work (Joules, J), Force (Newtons, N), and Distance (meters, m). Use Slides 4-5 .
Practice (5 min): Solve 2-3 simple problems together. Example: "Pushing a cart with 10N for 5m = 50J." Use Slide 6 .
03 Explain: The Direction Matters 10 MIN
The Direction Rule (5 min): Force and distance must be in the same direction .on the bag .Slides 7-8 .
Energy Transfer (5 min): Briefly connect work to energy transfer: Work is how energy moves or changes form. Use Slide 9 .
04 Apply & Wrap-up: Work Detectives 10 MIN
Sorting Activity (8 min): Groups categorize scenario cards as "Work" or "Not Work". Circulate to check for the "carrying horizontally" misconception.
Wrap-up (2 min): Review a few tricky cards as a class. Reinforce that in science, "work" is a precise calculation, not a feeling of tiredness. Use Slide 10 .
Are You Doing Work Slides Are You Working?
...or just moving stuff?
7th Grade Physics
Welcome students and introduce the day's question. Ask them to think about what 'work' means in their daily lives. Encourage a variety of answers.
What is "Work"?
What comes to mind when you hear the word work?
Chores?
Homework?
A Job?
Effort?
Welcome students and introduce the day's question. Ask them to think about what 'work' means in their daily lives. Encourage a variety of answers.
Is This "Work"?
Discuss with a partner:
Scenario 1
Lifting a heavy box off the floor.
Work or Not?
Scenario 2
Pushing as hard as you can against a brick wall that doesn't move.
Work or Not?
Guide students through the Think-Pair-Share. Give them a few minutes to discuss with their partners before bringing the class back together. Listen for common misconceptions.
The Scientific Definition
In science, work is done when a force causes an object to move a distance in the direction of the force.
It's not just about effort or feeling tired!
Introduce the scientific definition of work. Emphasize that it's different from how we use the word 'work' in everyday language.
The Key Ingredients
For scientific work to happen, you need all three:
1
A Force acting on an object.
2
The object must move a Distance.
3
The movement is in the Same Direction as the force.
Reinforce the two key components: force and distance. Use the desk demonstration mentioned in the lesson plan. Connect it to the definition.
Calculating Work
W = F × d
Work = Force × Distance
W = Work
Joules (J)
F = Force
Newtons (N)
d = Distance
meters (m)
Introduce the formula for work. Explain each variable and the standard units. Clarify that Joules are the unit for work (and energy).
Practice Time!
Quick Math
Problem 1
A student pushes a cart with a force of 10 Newtons (N) for a distance of 5 meters (m).
How much work is done?
W = F × d
W = ____________________
Present a simple practice problem for students to solve. Encourage them to write down the formula, plug in values, and state the units.
Work or Not Work Sorting Activity Work or Not Work?
Sorting Lab: The Scientific Definition of Work
Name:
Date:
Lab Instructions
Read each scenario below. Decide if scientific work is being done on the object mentioned. Sort the scenarios into the categories below by writing the card number in the correct box. Be prepared to explain why using the scientific definition: \(W = F \times d\) and the direction of force/motion.
1
A student lifts a 2 kg textbook 1 meter off the floor.
2
A person pushes with all their might against a large, unmoving boulder.
3
A waiter carries a tray of food horizontally across a crowded room.
4
A car pulls a trailer 100 meters down a straight, flat road.
5
A book falls from a shelf to the floor (consider gravity acting on the book).
6
You hold a heavy grocery bag steady while standing still.
7
A child pulls a toy wagon with a rope across the playground.
8
A satellite orbits the Earth at a constant speed (gravity acts inward, motion is perpendicular).
9
A painter pushes a roller upward across a high ceiling.
10
A student sits and studies for an exam for three hours.
WORK IS DONE
NO WORK IS DONE
Reflect: Choose one from the "NO WORK" list and explain why it doesn't count as scientific work.
Work Sorting Answer Key Answer Key
Work or Not Work? Sorting Activity
Teacher Resource
WORK IS DONE
Card 1: Lifting Textbook
Force is UP, motion is UP. Direction matches!
Card 4: Pulling Trailer
Force is FORWARD, motion is FORWARD.
Card 5: Falling Book (Gravity)
Force of gravity is DOWN, motion is DOWN.
Card 7: Pulling Wagon
Force is FORWARD, motion is FORWARD.
Card 9: Pushing Roller
Force is UP (against ceiling), motion is UP/Across.
NO WORK IS DONE
Card 2: Unmoving Boulder
Reason: Distance = 0. No movement = No work.
Card 3: Carrying Tray Horizontally
Reason: Force is UP, but motion is FORWARD. Directions are perpendicular.
Card 6: Holding Bag Steady
Reason: Distance = 0. Even if it's hard to hold, no work is done on the bag.
Card 8: Orbiting Satellite
Reason: Gravity is inward, but the satellite moves in a tangent path. No work done by gravity.
Card 10: Studying for Exam
Reason: Mental effort is not scientific work. No force/distance applied to an object.
Common Student Pitfalls
The "Effort" Error: Students think because someone is sweating or tired (Card 2, Card 6), they must be doing work. Remind them that without distance (\(d=0\)), \(W=0\).The "Direction" Dilemma: Cards 3 and 8 are the hardest. Emphasize that force must cause the motion. If the force is up but motion is forward, the force didn't cause the motion. 
