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Force Detectives

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Sheela Pagkalinawan

Tier 1
For Schools

Lesson Plan

Force Detectives Lesson Plan

Students will investigate how pushes and pulls (forces) affect the motion of objects by conducting simple experiments, recording observations, and drawing conclusions.

Understanding forces builds foundational physics knowledge and critical thinking, linking classroom concepts to everyday phenomena like pushing doors or rolling balls.

Audience

Middle School Students (7th Grade)

Time

30 minutes

Approach

Hands-on experiments, demonstrations, and guided discussion.

Materials

  • Spring Scale, - Toy Cars, - Inclined Plane or Ramp, - Various Masses (e.g., small weights), - Stopwatch or Timer, - Meter Stick or Measuring Tape, - Investigating Forces Worksheet, - Forces Exit Ticket, - Whiteboard and Markers, and - Computer/Projector for Demonstration

Prep

Material Preparation

5 minutes

  • Gather all physical materials: spring scale, toy cars, ramps, masses, stopwatches, meter sticks.
  • Print enough copies of Investigating Forces Worksheet and Forces Exit Ticket for each student.
  • Set up demonstration area with a flat surface and ramp.
  • Queue up any images or video clips showing real-world pushes and pulls for the hook.

Step 1

Hook: Everyday Forces

5 minutes

  • Project or show pictures/videos of people opening doors, pushing shopping carts, or kicking balls.
  • Ask students: “What forces are at work here? Can you identify the push or pull?”
  • Record student responses on the whiteboard under “Pushes” and “Pulls.”

Step 2

Teacher Demonstration

5 minutes

  • Use a spring scale to pull a block across the flat surface.
  • Ask students to predict how increasing or decreasing the pull will affect motion.
  • Pull with different forces and measure how far the block travels in 5 seconds.
  • Record observations and discuss the relationship between force magnitude and motion.

Step 3

Guided Investigation

15 minutes

  • Divide students into pairs and distribute materials and the Investigating Forces Worksheet.
  • Instruct pairs to set up a ramp and measure a fixed distance down the incline.
  • Have students use the spring scale to apply three different force levels to the toy car and time its motion over the measured distance.
  • Students record force values, times, and calculate speed on the worksheet.
  • Circulate to support data collection, safety, and accurate measurements.

Step 4

Share & Discuss

3 minutes

  • Invite a few pairs to share their data and conclusions.
  • Discuss patterns: “How did changing the force affect the car’s speed? Were there any anomalies?”
  • Emphasize that greater force generally produces greater acceleration, linking to Newton’s laws.

Step 5

Exit Ticket Assessment

2 minutes

  • Distribute the Forces Exit Ticket.
  • Ask students to define a push and a pull and give one real-world example of each.
  • Collect exit tickets to gauge understanding and inform future instruction.
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Slide Deck

Force Detectives: Investigating Forces

Welcome, 7th graders!

Today’s Objective:

  • Investigate how pushes and pulls affect the motion of objects

Get ready to think like real detectives of force!

Welcome students to the lesson “Force Detectives.” Introduce yourself and today’s objective: investigating how pushes and pulls affect motion through demos and hands-on experiments. Explain why understanding forces matters in everyday life.

Lesson Objectives & Agenda

Objectives:

  • Define push and pull
  • Observe how varying force changes motion

Agenda:

  1. Hook: Everyday Forces (5 min)
  2. Teacher Demonstration (5 min)
  3. Guided Investigation (15 min)
  4. Share & Discuss (3 min)
  5. Exit Ticket (2 min)

Review the goals and outline the flow of today’s lesson so students know what to expect.

Play the clip of people pushing/pulling objects. Ask: “What forces do you see? Are they pushes or pulls?” Record quick responses.

What Is a Force?

  • A force is a push or pull on an object.
  • Forces can change an object’s speed or direction.

Examples:

  • Opening a door (push)
  • Tug-of-war (pull)

Define forces and prompt students for examples. Clarify that all forces are either pushes or pulls and can speed up, slow down, or change an object’s direction.

Teacher Demonstration

  1. Attach block to spring scale on flat surface.
  2. Predict: How will increasing the pull affect motion?
  3. Pull with low, medium, and high force; each time, measure how far the block travels in 5 seconds.
  4. Record and compare distances.

Perform this demonstration step by step. Ask students to predict outcomes before each test and measure distances. Record results on the board.

Guided Investigation

  • Pair up and collect materials.
  • Set up ramp and mark a fixed distance.
  • Use spring scale to apply three different forces to the toy car.
  • Time the car as it travels the marked distance.
  • Record force, time, and calculate speed on the Investigating Forces Worksheet.

Guide pairs to set up safely and ensure accurate measurements. Circulate to answer questions and check that data are recorded correctly on the worksheet.

Share & Discuss

  • Which force produced the highest speed?
  • Did any results surprise you?
  • How does changing force relate to acceleration?

Invite 2–3 pairs to share their data and conclusions. Highlight the trend: greater force → greater speed/acceleration. Relate observations back to Newton’s laws.

Exit Ticket

Complete the Forces Exit Ticket:

  1. Define a push and give one real-world example.
  2. Define a pull and give one real-world example.

Distribute exit tickets and explain the task. Collect as students finish to gauge understanding before moving on.

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Worksheet

Investigating Forces Worksheet

Objective

Use a spring scale to apply three different forces to a toy car on a ramp. Measure the time it takes to travel a fixed distance, then calculate the car’s speed for each trial.

Materials

  • Spring scale
  • Toy car
  • Inclined plane (ramp)
  • Stopwatch or timer
  • Meter stick or measuring tape
  • This worksheet

Setup and Procedure

  1. Mark a fixed distance (e.g., 1 m) on the ramp.
  2. Attach the spring scale to the toy car.
  3. Keep the ramp angle constant for all trials.
  4. Apply three different forces (e.g., low, medium, high) using the spring scale and release the car from the start line.
  5. Use the stopwatch to record how long it takes the car to travel the marked distance.
  6. Record values in the data table below and calculate speed using the formula:
    speed = distance ÷ time

Data Table

TrialForce Applied (N)Time (s)Distance (m)Speed (m/s)
1
2
3

Observations & Calculations

  1. Show your calculations for speed (show each distance ÷ time) for all three trials below:










Analysis Questions

  1. What trend do you observe between the force applied and the speed of the car? Explain your answer.











  1. Did you notice any anomalies or unexpected results in your data? Suggest possible reasons for these results.











  1. Based on your data, if you wanted the car to go twice as fast as in Trial 1, would you need to apply more force, less force, or the same force? Explain your reasoning.











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Worksheet

Forces Exit Ticket

  1. Define a push in your own words:




  1. Give one real-world example of a push:




  1. Define a pull in your own words:




  1. Give one real-world example of a pull:




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