Attaching padlocks, especially to bridge railings, has been a popular trend among newly in love couples for years as a symbol of their love. However, in several cities padlocks have already been removed because they block the passage and the total weight of the locks should endanger the safety of the bridge?
Do you share the safety concerns if a bridge is hung with love locks?
Is there anything more romantic than professions of eternal love to your partner? If you look closely, they can be found in almost every city: countless bridge railings are hung with so-called „Love locks“. Some of these locks are engraved, some colorfully painted with the lover’s names, again other’s origins remain secret . But there is one thing they all have in common: They symbolize the attachment and devotion of the people who put them there. But what happens, when there are too many love locks on a bridge? Or when the bridge has to be renovated? Last year quite a few locks had to be removed from the railway bridge in Cologne due to the fact that they were partially blocking the bikeway. In some cities the locks had to be removed just as a result of the sheer weight they add to the bridge.
But exactly how much additional weight does a bridge actually have to carry if it’s hung with love locks? And how long would it take to remove all of the locks? Begin by considering how many love locks could approximately be hanging on a well-known bridge (like the railway bridge in Cologne). Inform yourself about how much money you could get by giving away the iron from the padlocks. What charity do you think a city should donate the money to?
There is obviously not an exact solution to this problem.
First we start with a question: How much is the overall weight of all the padlocks on the bridge?
The solution depends on physical factors as
We have to start with some assumptions:
Under these assumptions, we get
This is the weight of approximately 100 Persons which should not be a problem for a bridge. However, this result can be refined in various ways.
As long as simple physical concepts such as weight have been introduced, this task can be used at almost any age level. However, a basic understanding of geometry helps to create comparatively accurate solutions.
The Question of the padlocks overall weight depends on several uncertainfactors, i.e. avarage weight of the padlocks, geometry of the bridge (lenght, type of railings, density of the padlocs etc).
Students must make certain assumptions and use them to design a mathematical model that describes the ultimate load of the bridge. The model is then validated and revised if necessary.
IBL is characterized as follows: Students…
• create their own scientifically oriented questions;
• give priority to evidence in responding to questions;
• ormulate explanations based on evidence;
• connect explanations to scientific knowledge;
• communicate and justify explanations
Conclusion: IBL tasks are self differentiating tasks
Usually, students process an IBL task as follows (Research Cycle)
1. Formulate a specific question (Ask)
2. Use the existing knowledge to understand the problem and investigating possible solutions (Investigate)
3. Create new findings based on the previous findings (Create)
4. Discuss the findings (Discuss)
5. Evaluate the result and, if necessary, improve the solution (Reflect)
• Are accessible by all students
• Provide achievable challenges
• Develop fluency, understanding and processes
• Offer multiple entry points
• Involve using a range of methods and strategies
• Value the process rather than the answer
The role of a teacher in using IBL in STEM education
• Looks into and challenges student thinking and reasoning
• Instigates the evaluation and communication of strategies
• Uncovers misconceptions
• Supports student to learn from mistakes
• Provokes and stimulates the exploration of alternative routes