# Pascal's Principle - Example 2

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,
1. what gauge pressure in Pa must be applied to the oil?
2. 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
$A 2 =π r 2 =π (1) 2 =π m 2$ Pressure of the oil
$P= F A P= 50,000 π =15,900Pa$ b.
Area of the small piston
$A 1 =π r 2 =π (0.05) 2 =0.0025π m 2$ According to the Pascal's Principle, $F 1 A 1 = F 2 A 2 F 1 (0.0025π) = (50,000) π F 1 = (50,000)(0.0025π) π =125N$