What is the primary purpose of a bridge?

• To serve as a monument or landmark

• To provide safe passage over physical obstacles

• To generate electricity from flowing water

• To act as a barrier between communities

Approximately how many bridges are there in the United States?

• Around 50,000

• Around 100,000

• Over 617,000

• Exactly 1 million

What two fundamental forces must engineers balance when designing a bridge?

• Gravity and friction

• Wind and water pressure

• Compression and tension

• Shear and torsion

What do the blue and red colors represent in bridge design diagrams?

• Blue represents tension, red represents compression.

• Blue represents compression, red represents tension.

• Blue represents dead load, red represents live load.

• Blue represents strong members, red represents weak members.

What is the difference between a dead load and a live load on a bridge?

• Dead load is the weight of the bridge itself, while live load is the weight of objects crossing it.

• Dead load is the weight of objects crossing the bridge, while live load is the weight of the bridge itself.

• Dead load refers to environmental factors, while live load refers to the bridge's own weight.

• Dead load is the maximum weight a bridge can hold, while live load is the average weight it holds.

An engineer designs a bridge where one of its members is made significantly smaller than the others. What is the most likely outcome when this bridge is tested?

• The bridge will be more aesthetically pleasing due to the varied member sizes.

• The bridge will be more cost-effective and equally strong.

• The bridge member will likely fail, making the bridge unsafe or non-functional.

• The bridge will become more flexible, improving its resistance to wind shear.

Why is stone considered a poor material choice for building long bridges?

• It is too heavy, leading to a high dead load.

• It is prone to rusting and requires high maintenance.

• It is difficult to shape into iconic arch structures.

• It is not readily available in all regions.

What is a primary advantage of using steel in bridge construction compared to iron?

• Steel is more resistant to corrosion.

• Steel is lighter and stronger, enabling longer spans.

• Steel is easier to cast into complex shapes.

• Steel is a more traditional material for bridges.

Which variable has a cubic relationship with a beam's deflection, meaning a small change in this variable can lead to a large change in deflection?

• Material or Elasticity (E)

• Shape (Inertia) (I)

• Length (L)

• Force or Pressure (F)

What was the main lesson learned from the paper bridge challenge regarding bridge construction?

• The cost of materials is the most critical factor.

• The shape and design of a bridge are crucial for its strength.

• Longer bridges are inherently more stable.

• Only specific materials like metal can create strong bridges.