**Example 1**:

In a hydraulic system the large piston has a cross-sectional area A_{2} = 200 cm² and the small piston has cross-sectional area A_{1} = 5 cm². If a force of 250 N is applied to the small piston, what is

a. the pressure exerted on the small piston

b. the force F, produced on the large piston?

**Answer**:

a. Pressure exerted on the small piston

b. Pressure exerted on the large piston = Pressure exerted on the small piston

**Example 2**:

A hydraulic lift is to be used to lift a truck masses 5000 kg. If the diameter of the small piston and large piston of the lift is 5cm and 1 m respectively,

- what gauge pressure in Pa must be applied to the oil?
- What is the magnitude of the force required on the small piston to lift the truck?

**Answer**:

a. Weight of the truck,

W = mg

W = (5000)(10) = 50,000N

Area of the big piston

A_{2} =πr^{2}

=π(1)^{2}

=πm^{2}

Pressure of the oil

b.

Area of the small piston

A1 =πr^{2}

=π (0.05)^{2}

=0.0025π m^{2}

According to Pascal’s Principle,

**Example**:

Figure above shows a hydraulic system. The area of surface X is 5 cm² and the area of surface Y is 100 cm². Piston X has been pushed down 10cm. what is the change of liquid level, h, at Piston Y?

**Answer**:

Distance move by the piston-X, h_{1} = 10cm

Distance move by the piston-Y, h_{2} = h

Area of piston-X, A_{1} = 5 cm²

Area of Piston-Y, A_{2} = 100 cm²