Application of Newtons Laws FORCES AND BRIDGE BUILDING

Application of Newton’s Laws FORCES AND BRIDGE BUILDING

Goals: 1. Identify the different forces that act on a bridge. 2. Compare and contrast compression and tension. 3. Recognize and apply Newton’s three laws of motion to bridge building.

Golden Gate Bridge (suspension bridge) – San Francisco, USA

Millau Viaduct (cable-bridge) – southern France

Chengyang Bridge (no nails or rivets) – Near Linxi River, China

Stari Most (arch bridge) – Mostar, Bosnia and Herzegovinia

Watch the video and answer the questions: What forces do you think are acting on the bridge? Why do you think the bridge collapsed? How do you think Newton’s laws of motion involved in the construction of a bridge?

Loads on a Bridge Load: Creates a force on a structure. Dead Load: Live Load:

Draw a free-body diagram of some of the forces you think are acting on the bridge.

Other Forces With your partner standing across from you place your palms together and slowly lean towards each other. How do your arms feel?

Other Forces This is an example of compression! Compression: Pressing force that “pushes” material together. Which parts of a bridge do you think have a compression force? Why?

Other Forces With your partner standing across from you, link fingers as shown and lean away from each other. How do your arms feel?

Other Forces This is called tension! Tension: Pressing force that “pulls” material apart. Which parts of a bridge do you think have a tension force?

Make a Prediction Do you think that all types (and shapes) of bridges can handle the same types of forces? Why or why not?

In Class Activity – Paper Bridge Can you build a bridge that holds 50 coins, using 2 sheets of paper, and no more than 5 paper clips? You Must: - work in teams of 4 - complete the challenge in 15 minutes

Journal Entry What forces do engineers have to consider when they are building bridges? Why do you think a bridge might collapse (fall down)? Explain how you think Newton’s laws of motion apply to building a bridge. Use examples.