FORM 4: 3.4 APPLYING PASCAL'S PRINCIPLE

PASCAL’S PRINCIPLE

Pascal’s principle states that pressure applied to an enclosed liquid is transmitted equally to every part of the liquid.

HYDRAULIC SYSTEMS

Pressure is transmitted uniformly throughout an enclosed liquid.

APPLICATIONS OF PASCAL’S PRINCIPLE

HYDRAULIC JACK

1.     When a small piston is pushed, valve A closes and valve B opens.

2.     Hydraulic oil is forced through valve B and raises the big piston.

3.     When the small piston is pulled up, valve B closes and valve A opens.

4.     Hydraulic oil is drawn from the reservoir into the space under the small piston.

5.     Continuous up and down movements of the small piston will cause the big piston to move up to lift the car.

6.     When the release valve is opened, the weight of the car will force the big piston downward, pushing the hydraulic oil into the reservoir. The car will be lowered to its original position.

HYDRAULIC BRAKE

1.     When the driver’s foot presses the brake pedal, the piston in the master cylinder exerts pressure on the brake fluid.

2.     This pressure is transmitted to the wheel cylinder of all wheels.

3.     The pressure causes the pistons to press the brake shoes against the wheels to slow down the car.