Explanation:

Bridges are designed to support a certain amount of weight. When too many people stand on a bridge, it can collapse due to an increase in stress. This is because the weight of the people is added to the weight of the bridge itself, which can cause the structure to become overloaded.

Factors that contribute to increased stress on a bridge:

1. Weight: Bridges are designed to carry a specific weight load, and exceeding this load can cause stress on the structure. The weight of a person can vary depending on their size, but even a small increase in weight can contribute to stress on the bridge.

2. Movement: When people walk or jump on a bridge, their movement can cause additional stress on the structure. This can be particularly dangerous if the bridge is already overloaded.

3. Environmental factors: Bridges can also be affected by environmental factors such as wind, temperature changes, and natural disasters like earthquakes or floods. These factors can cause stress on the structure and contribute to its collapse.

Prevention:

To prevent bridge collapse due to stress, it is important to adhere to weight limits and other safety guidelines. It is also important to properly maintain and inspect bridges to ensure that they are structurally sound. Regular inspections can help identify potential issues and allow for repairs to be made before they become more serious.

Conclusion:

Bridges are essential structures that allow for safe passage over waterways, gorges, and other obstacles. However, they can become dangerous if they are overloaded or not properly maintained. By understanding the factors that contribute to bridge collapse and taking steps to prevent it, we can ensure that bridges remain safe and reliable for years to come.