Why is the reaction force angled upwards on a flat drawbridge?

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In summary, the conversation discusses the concept of reaction forces on a flat bridge and why the force from the wall is angled upwards rather than horizontal. The conversation also touches on the role of friction in keeping the bridge from falling.
  • #1
danago
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Hi. Not directly a specific homework question, but it will help with some of my questions.

When the bridge is flat, why is the reaction force from the wall on the bridge angled upwards? Why is it not horizontal, along the length of the bridge?

Sorry if i was a little vague.

Thanks,
Dan.
 
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  • #2
If the force were only horizontal, how would that keep it from falling? I'm also sorry to be vague.
 
  • #3
Hmm ok. If it was a frictionless wall, would it be possible for an angled reaction force to exist?
 
  • #4
I don't understand the situation. Are you saying that the drawbridge is held up by friction? How is the bridge attached to the wall? What pulls the bridge up and down?
 
  • #5
Nearest I can come to having it make sense is that the bridge is being compressed against the wall. So there two forces. There is the horizontal wall reaction force to the normal force of compression. And there would be a vertical static frictional force holding the thing up. So the combination of these two forces can be 'angled upwards'. If it's a frictionless wall, the bridge will fall.
 
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FAQ: Why is the reaction force angled upwards on a flat drawbridge?

What are the reactions on a drawbridge?

The reactions on a drawbridge are the forces that act on the bridge to keep it stable and balanced. These reactions include the vertical reaction, which supports the weight of the bridge and any loads on it, and the horizontal reaction, which resists any lateral forces such as wind or water currents.

How are the reactions on a drawbridge calculated?

The reactions on a drawbridge are calculated using the principles of statics, which involves balancing the forces and moments acting on the bridge. The weight and distribution of the bridge, as well as any external loads and the geometry of the bridge, are taken into account when determining the reactions.

What factors can affect the reactions on a drawbridge?

The reactions on a drawbridge can be affected by various factors, including the weight and distribution of the bridge itself, the weight of any vehicles or pedestrians on the bridge, wind and water currents, and the geometry and design of the bridge.

How do the reactions on a drawbridge change when the bridge is in motion?

When a drawbridge is in motion, the reactions on the bridge will change as the weight and distribution of the bridge shifts. For example, as the bridge begins to open, the vertical reaction will decrease as the weight of the bridge is transferred to the horizontal reaction. Similarly, as the bridge closes, the horizontal reaction will decrease and the vertical reaction will increase.

What safety measures are in place to ensure the drawbridge reactions are within safe limits?

Drawbridges are designed with safety factors in mind to ensure that the reactions on the bridge are within safe limits. These safety factors include designing the bridge to withstand higher loads than it is expected to encounter, regular inspections and maintenance, and emergency protocols in case of unforeseen circumstances, such as extreme weather conditions.

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