Question

What is a hydraulic jack?

Answer 1

Hint : A hydraulic jack can be defined as a device that can be used to lift some weight with the help of a hydraulic control. It must be noticed that this hydraulic control consists of a cylinder and a piston which transfers the pressure that is applied on a small area to a surface that has a bigger area.

Complete step-by-step solution:
Hydraulic jack is a device based on Pascal’s law that helps to lift heavy objects such as a car by transmitting the force applied on a small area to a surface of larger area. The principle on which the hydraulic jack works is Pascal's law. So let us first discuss Pascal's law. According to Pascal’s law, if a pressure difference is enforced on a fluid enclosed in a chamber, the pressure will be transmitted without any change throughout the fluid and also to the walls of the container. The reason behind this is the free movement of atoms in an enclosed fluid which makes it possible for the pressure to reach anywhere. A simple diagram to illustrate the working of hydraulic jack that is used to lift a car by applying the force on a small area is as follows:

Note: The force that needs to be applied on the smaller piston is directly proportional to the weight of the car and the area of the smaller pistons and is inversely proportional to the area of the larger piston. Hence, we can conclude that to minimize the force that needs to be exerted on the smaller piston we must increase the area of the larger piston and decrease the area of the smaller piston.