Scenario: Engineering Design - Learn systematic approaches to tackle complex problems!
You're designing a bridge to connect two parts of a city park. The bridge needs to span 24 meters across a stream. You have budget constraints: maximum cost $15,000, and you need to support at least 50 people (average 70 kg each) plus the bridge's own weight. Available materials cost: steel $200/meter, concrete $150/meter, wood $100/meter.
Engineering Challenge:
Design the most cost-effective bridge that meets all safety requirements.
Physical Requirements:
Budget Constraints:
What exactly are we trying to solve?
What information do we have?
Explore different approaches:
Option 1: Steel Bridge
Cost = 24 meters × $200/meter = $4,800
Status: ✅ Within budget, very strong
Option 2: Concrete Bridge
Cost = 24 meters × $150/meter = $3,600
Status: ✅ Within budget, very durable
Option 3: Wood Bridge
Cost = 24 meters × $100/meter = $2,400
Status: ✅ Within budget, most cost-effective
Safety Factor: All materials can support the required load, but steel and concrete are more reliable for long-term use.
Maintenance: Wood requires more maintenance, concrete and steel are more durable.
Environmental Impact: Wood is most environmentally friendly, steel is recyclable.
| Criteria | Weight | Steel | Concrete | Wood |
|---|---|---|---|---|
| Cost | 40% | 3/5 | 4/5 | 5/5 |
| Durability | 30% | 5/5 | 5/5 | 3/5 |
| Maintenance | 20% | 4/5 | 5/5 | 2/5 |
| Environment | 10% | 3/5 | 2/5 | 5/5 |
Recommended Solution: Concrete Bridge
• Cost: $3,600 (well within budget)
• Excellent durability and low maintenance
• Can support the required load safely
• Good balance of cost and performance
Design a rectangular garden for your school. You have 100 meters of fencing. The garden should be at least 400 square meters. What dimensions give you the largest possible garden area?
Your solution strategy:
A school needs to transport 200 students to a field trip. Buses can carry 40 students each and cost $300 per trip. Vans can carry 8 students each and cost $80 per trip. What's the most cost-effective combination?
Your analysis: