Applications of Elasticity Concept of CBSE Class 11 - Extramarks

Summary

The video explains the mechanics of cranes and bridges, emphasizing the importance of material properties in construction. It details how cranes use thick metallic ropes to lift heavy loads, with their diameter determined by the elastic limit and weight. The discussion extends to bridges, which rely on I-shaped beams to support traffic and their own weight. Over time, bridges can lose their elastic properties, leading to increased strain and potential structural failure. This highlights the need for proper design and maintenance to ensure safety and integrity in construction.

Takeaways

• 🛠️ Cranes use thick metallic ropes to lift heavy loads on construction sites.
• 📏 The diameter of the rope is determined by its elastic limit and the load it must carry.
• ⚖️ Increasing the load on the metallic rope leads to deformation due to stress and strain.
• 🔗 The strength of metallic ropes is influenced by the material used and its diameter.
• 🏗️ I-shaped beams are commonly used in bridge construction for structural support.
• 🚧 Bridges must be designed to handle the weight of traffic and their own structure.
• ⏳ Over time, bridges can lose their elastic properties, increasing strain under stress.
• ⚠️ Prolonged use of bridges can lead to structural failure and collapse.
• 🔍 Safety inspections are crucial for determining the usability of aging bridges.
• 💡 Understanding the mechanics of construction materials is essential for engineering safety.

Q & A

What is the role of cranes on construction sites?

Cranes are used to lift heavy loads, facilitating the construction process by moving materials to different locations.

What governs the required diameter of the metallic rope used in cranes?

The diameter of the metallic rope is determined by the rope's elastic limit and the load that it is expected to lift.

What happens to a metallic rope when the load increases?

When the load on a metallic rope is increased, the rope may deform due to the increased stress and strain placed upon it.

How does the strength of metallic ropes vary?

The strength of metallic ropes depends on the type of material used and the diameter of the rope.

What type of beams are commonly used in bridge construction?

I-shaped beams are commonly used in the construction of bridges as they provide a strong support system.

What factors must be considered in the design of bridges?

Bridges must be designed to withstand the load of traffic and their own weight, ensuring they remain safe over time.

What can happen to a bridge over long-term use?

Over long-term use, a bridge can lose its elastic properties, leading to increased strain for a given level of stress.

What does increased strain in a bridge indicate?

Increased strain in a bridge indicates that the material is deforming more than expected under the applied stress, which can compromise structural integrity.

Why are bridges declared unsafe after prolonged use?

Bridges are declared unsafe after prolonged use because the loss of elastic properties can lead to potential collapse under regular load conditions.

What is the significance of inspecting cranes and bridges regularly?

Regular inspections of cranes and bridges are crucial to ensure their structural integrity and safety, preventing failures and accidents.