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🌉 Week 10: Bridge Engineering

Lesson Overview
Grade Level Grades 3-4
Duration 40 minutes
STREAM Focus E (Engineering), M (Math)

Week 10: Bridge Engineering

🎯 Learning Objectives

STEM Objectives

Students will be able to: 1. Identify and compare different bridge types 2. Understand how forces (tension, compression) affect bridges 3. Design and build a bridge meeting specifications 4. Calculate efficiency ratios

Faith Integration Objectives

Students will be able to: 1. Connect bridge metaphors to faith (Jesus as bridge) 2. Understand reconciliation as bridge-building 3. Recognize the importance of connecting communities

Week 10: Bridge Engineering

🙏 Faith-Reason Integration

Catholic Teaching Connection

Jesus as Bridge — Jesus reconciled humanity with God, bridging the gap caused by sin. In our lives, we're called to be bridge-builders too — connecting people, resolving conflicts, and bringing communities together.

Scripture Connection

"For there is one God and one mediator between God and mankind, the man Christ Jesus." — 1 Timothy 2:5

Saint Connection

St. John Nepomucene — Patron saint of bridges. This priest was martyred on a bridge in Prague. Bridges throughout Europe bear his statue, reminding us that some things are worth standing firm for.

📚 Materials Needed

  • Pictures of different bridge types

  • Building materials: straws, tape, paper, craft sticks

  • Weights for testing (pennies, small objects)

  • Gap to span (12 inches between books/blocks)

  • Recording sheets

  • Calculators

📝 Lesson Procedure (40 minutes)

Opening Prayer & Introduction (5 min)

Prayer: "Lord Jesus, You are the bridge between heaven and earth. Help us learn about bridges today and understand how to be bridge-builders in our own lives. Amen."

Hook: Show images of famous bridges (Golden Gate, Brooklyn Bridge, London Bridge).

  • "What do all bridges have in common?"

  • "Why do we need bridges?"

Bridge Types & Forces (10 min)

Explore bridge types:

1. Beam Bridge

  • Simple flat span

  • Best for short distances

  • Example: Log across stream

2. Arch Bridge

  • Curved shape pushes force outward

  • Very strong

  • Example: Roman aqueducts

3. Truss Bridge

  • Uses triangles for strength

  • Efficient use of materials

  • Example: Railroad bridges

4. Suspension Bridge

  • Cables hold up the deck

  • Best for long spans

  • Example: Golden Gate

Forces in bridges:

  • Compression — Squeezing force (pushing together)

  • Tension — Stretching force (pulling apart)

  • "Bridges must handle both forces!"

Quick demo: Show compression and tension with hands and a ruler.

Design Challenge (5 min)

Challenge specifications:

  • Span a 12-inch gap

  • Hold as much weight as possible

  • Use only provided materials (straws, tape, paper OR craft sticks)

  • Limited to 20 pieces of primary material

Team planning:

  • Which bridge type will you use?

  • Where will you put your strongest elements?

  • Sketch your design

Build Phase (12 min)

Teams build bridges.

Teacher circulates:

  • "What type of bridge are you building?"

  • "Where are the tension/compression forces?"

  • "How are you handling the load?"

Encourage:

  • Use triangles for strength

  • Test early and modify

  • Consider where weight will be placed

Testing & Analysis (6 min)

Test each bridge:

  • Place across gap

  • Add weights gradually (pennies work well)

  • Record maximum weight held

Calculate efficiency:

  • Efficiency = Weight held ÷ Pieces used

  • "Which bridge was most efficient?"

Compare designs:

  • What strategies worked best?

  • How did different bridge types perform?

Reflection & Closing (2 min)

Discussion:

  • "What would you do differently?"

  • "How do bridge engineers test their designs?"

Faith Connection: "Bridges connect what was separated. Jesus is our ultimate bridge — connecting us to God. But we're called to build bridges too: bridges of friendship, bridges of forgiveness, bridges of understanding. What bridge could YOU build this week?"

Closing Prayer: "Jesus, our Bridge to the Father, help us be bridge-builders. When there's conflict, let us bring peace. When there's division, let us bring unity. Make us connectors of people and communities. Amen."

✅ Assessment

  • Built bridge meeting span requirements

  • Applied understanding of bridge types

  • Tested and recorded results

  • Calculated efficiency ratio

  • Connected bridge concept to faith

📎 Home Connection

"We were bridge engineers! Ask your child: 'What type of bridge did you build?' 'What forces did you have to consider?' 'What makes bridges strong?' Talk about how Jesus is the bridge between us and God, and how we can be bridge-builders in our relationships — connecting people and resolving conflicts."

Lesson Version: 1.0 | **