Pascal's Principle

Pressure is transmitted undiminished in an enclosed static fluid.

Hydraulic Press

A multiplication of force can be achieved by the application of fluid pressure according to Pascal's principle, which for the two pistons implies 根据帕斯卡原理，通过流体压力可以实现力的乘积，这在两个活塞的情况下意味着 P1 = P2 This allows the lifting of a heavy load with a small force, as in an auto hydraulic lift, but of course there can be no multiplication of work, so in an ideal case with no frictional loss: 这使得可以用小力 lifting 重物，如汽车液压提升机，但当然无法乘以功，所以在理想情况下没有摩擦损失时： Winput = Woutput Calculation 计算 P1 = P2，Winput = Woutput

Hydraulic Press Calculation

Example of hydraulic press action. For piston radii: r1 = cm r1 = in and r2 = cm r2 = in the cylinder areas are A1 = m2 A2 = m2 and the force multiplication is A2/A1 = For an input force F1 = N F1 = lb, Pascal's principle gaurantees that P1 = P2 = kPa P1 = P2 = lb/in2. 液压机作用示例。对于活塞半径：r 1 = cm r 1 = in 和 r 2 = cm r 2 = in，缸的面积是 A 1 = m 2 A 2 = m 2，力放大比是 A 2 /A 1 =。对于输入力 F 1 = N F 1 = lb，帕斯卡原理保证 P 1 = P 2 = kPa P 1 = P 2 = lb/in 2。 中文译文中的待填/计算数值依次对应：1：r1 2：r1c 3：r2 4：r2c 5：a1 6：a2 7：a2a1 8：f1 9：f1c 10：p1 11：p1c。实际数值以上方原输入框为准。

Applying this pressure to the output cylinder yields the lifting force:

对输出缸施加这种压力会产生提升力：

F₂ = N = lb,

A price must be paid for an increased lifting force, since conservation of energy must be satisfied. For an ideal hydraulic press, the work must satisfy W_input = W_ouput, so that to lift the load a distance of

为了获得更大的提升力，必须付出代价，因为能量守恒必须得到满足。对于理想液压机，所做的功必须满足 W_input = W_output ，因此要提升负载一段距离，

d₂ = m = ft,
the input piston must be moved a distance
d₁ = m = ft,

F₂ = N = lb，d₂ = m = ft，输入活塞必须移动距离d₁ = m = ft，

中文译文中的待填/计算数值依次对应：1：f2 2：f2c 3：d2 4：d2c 5：d1 6：d1c。实际数值以上方原输入框为准。

Automobile Hydraulic Lift

A hydraulic lift for automobiles is an example of a force multiplied by hydraulic press, based on Pascal's principle. The fluid in the small cylinder must be moved much further than the distance the car is lifted.

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.