Very basic phisics, hydraulics and weights, wrong diagram?

In summary, the conversation discusses the concept of force multiplication in a hydraulic press, where a small amount of force is used to lift a large object. This is achieved by using a small piston to push fluid into a larger piston, resulting in a greater force being exerted on the larger object. The conversation also touches on the concept of work, where the distance moved by the small piston is greater than the distance moved by the large piston due to the conservation of work. This allows for a smaller force to lift a larger object.
  • #1
losbellos
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Hej Guys,

I am just wondering. See the picture.

weights.jpg


If I put 5kg on the right the water lever increases and the new water level on the left should be as much higher as 5kg volume of water. Its so obvious isn't it?

So if it is obvious can you please tell me that why it is possible that in a exactly the same
- http://hyperphysics.phy-astr.gsu.edu/hbase/pasc.html#hpress - diagram they hold a car with a fraction of the weight of a car on the left side?
I can't understand it how it would be possible...Thanks!
 
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  • #2
losbellos said:
So if it is obvious can you please tell me that why it is possible that in a exactly the same
- http://hyperphysics.phy-astr.gsu.edu/hbase/pasc.html#hpress - diagram they hold a car with a fraction of the weight of a car on the left side?
I can't understand it how it would be possible...

It's a force multiplier.

From the link:
For example, if the lift cylinder were 25 cm in diameter and the small cylinder were 1.25 cm in diameter, then the ratio of the areas is 400, so the hydraulic press arrangement gives a multiplication of 400 times the force. To lift a 6000 Newton car, you would have to exert only 6000 N/400 = 15 N on the fluid in the small cylinder to lift the car. However, to lift the car 10 cm, you would have to move the oil 400 x 10cm = 40 meters. This is practical by pumping oil into this small cylinder with a small compressor.

It works kind of like a wrench. A short wrench requires much more force to turn something than a longer wrench does. However, the longer wrench has to move a much greater distance. So you're trading distance moved for an increased force multiplier.

It's the same concept as me giving you a huge lever and you lifting up a tank with just your body weight.
 
  • #3
I understand what you write but then the 5kg/5kg example why true as well? can you help me understand that?
You see I feel troubled because this two example is somewhat opposing?

I have a feeling that we talk aside.. See this example. I if put 100 Newton force the other side 100 Newton force must come out. Not less force is enough top hold against 100 Newton force.
weigth2.jpg


or here is an other example. THere is the 100N push downwards that is distributes the force on the watered surface and then on the other side there will be less pressure? No it have to be 100 N + water weight.

In other way the pressure distribution on the wall doesn't make the object lighter down on the other side... Just think about this, its not possible thet a 10kg object would be lighter to hold up, because of...

weights4.jpg
 
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  • #4
Consider that work is force * distance. If you push a large amount of fluid with a large piston into a small piston, the small piston will move much farther than large piston. The work is conserved, so pushing on a large piston must reduce the force that the small piston pushes with, since the small piston moves farther.
 
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  • #5
yeah this is clear thanks!
 

1. What is the difference between weight and mass?

Weight is a measure of the force of gravity on an object, while mass is a measure of the amount of matter in an object. Weight can vary depending on the strength of gravity, while mass remains constant.

2. How do hydraulic systems work?

Hydraulic systems use the principle of Pascal's law, which states that pressure applied to a fluid in a closed system is transmitted equally in all directions. This allows for the transfer of force and energy through the system, making it possible to lift heavy objects with relatively small forces.

3. What is the relationship between force, mass, and acceleration?

According to Newton's second law of motion, force is equal to mass multiplied by acceleration. This means that the greater the mass of an object, the more force is needed to accelerate it, and the greater the acceleration, the more force is needed to maintain it.

4. Why is it important to use the correct diagrams in physics?

Inaccurate diagrams in physics can lead to incorrect understanding and application of concepts. They can also cause errors in calculations and experiments, leading to incorrect results and conclusions.

5. How does the center of mass affect an object's stability?

The center of mass is the point at which an object's mass is evenly distributed. An object's stability depends on the location of its center of mass - the lower and wider the center of mass, the more stable the object will be. If the center of mass is outside the object's base, it will be unstable and likely to topple over.

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