Min force to open the water gate

In summary, the question is asking why Fr(Lp) is equal to FB/2. The suggested solution is 2FB = Fr(Lp), but the correct answer is Fb/2 because F acts at b/2 from the hinge and only on one side. The author's drawing of a 45 degree angle and the placement of the hinge at point B are unconventional, and the horizontal line at 3 m is meant to represent a sturdy material.
  • #1
werson tan
183
1

Homework Statement


why Fr(Lp) = FB / 2 ? can someone help to explain ?

Homework Equations

The Attempt at a Solution


shouldn't it be 2FB = Fr(Lp) ? since FB act on 2 sides of the gate ...[/B]
 

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  • #2
It's Fb/2 because F acts at b/2 from the hinge. It only acts on one side.
Fr acts at Lp from the hinge on the other side.
 
  • #3
Author sure has a funny way of drawing a 45 degree angle !
And conspicuously does not draw a hint of a hinge at B.

Furthermore, the horizontal line at 3 m is supposed to designate something sturdy that has water above and air below ? Quite something different from the liquid surface at 4.2 m; more like the stuff the gate itself should be made of. Deceptive drawing, incompetence, sloppiness ?
 

Related to Min force to open the water gate

1. What is the minimum force required to open a water gate?

The minimum force required to open a water gate depends on various factors such as the size and weight of the gate, the water pressure, and the friction between the gate and its hinges. It is usually determined through calculations and testing, but on average, it can range from a few pounds to several hundred pounds.

2. How is the minimum force to open a water gate calculated?

The minimum force to open a water gate is calculated by taking into account the weight of the gate, the water pressure acting on it, and the coefficient of friction between the gate and its hinges. This calculation is based on Newton's Second Law of Motion, which states that force equals mass multiplied by acceleration.

3. Can the minimum force to open a water gate be decreased?

Yes, the minimum force to open a water gate can be decreased by reducing the weight of the gate, increasing the size of the gate, or reducing the friction between the gate and its hinges. It can also be decreased by adjusting the water pressure or using a mechanical advantage, such as a lever or pulley system.

4. What are the potential consequences of using too much force to open a water gate?

Using too much force to open a water gate can result in damage to the gate, its hinges, or the surrounding infrastructure. It can also cause injury to the person operating the gate or anyone in the vicinity. Additionally, using excessive force can lead to increased wear and tear on the gate, leading to a shorter lifespan and higher maintenance costs.

5. How can the minimum force to open a water gate be measured?

The minimum force to open a water gate can be measured using a force gauge or a load cell. These devices can accurately measure the amount of force needed to open the gate and provide data for further calculations. It is important to regularly measure and monitor the force required to open a water gate to ensure it is functioning properly and to detect any changes or issues that may arise.

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