Oil is a liquid. State the property of a liquid that makes it suitable for use in a hydraulic system.
Explain, in molecular terms, why a liquid has this property.
Suggest one advantage of using oil as the liquid in a hydraulic press.
The cross-sectional area of piston 1 is $0.018\,\text{m}^2$. Piston 1 exerts a force of $4500\,\text{N}$ on the oil. Calculate the pressure of the oil caused by this force.
The pressure of the atmosphere is $1.0\times10^5\,\text{Pa}$. Calculate the total pressure of the oil in the pipe.
The area of piston 2 that is in contact with the oil is $1.4\,\text{m}^2$. Calculate the force exerted on piston 2 caused by the pressure calculated in (c)(ii).
Explain why the pressure at the upper surface of piston 2 increases.
The density of the oil is $900\,\text{kg m}^{-3}$. The upper surface of piston 2 is now $0.50\,\text{m}$ below the level of the pipe. Calculate the increase in the force exerted on the upper surface of piston 2 by the oil. $g = 10\,\text{N kg}^{-1}$.
There is air trapped in the plastic bags that contain the waste. The temperature of the air in the bags remains constant. Explain, in terms of molecules, why the pressure of the trapped air rises as it is compressed.