Hydraulic Brakes and hydraulic lift

 HYDRAULIC BRAKES

The working of hydraulic brakes is based on pascal's law.
construction. It consists of a mater cyclinder M filled with brake oil and provided with air tight frictionless piston P.
The piston is  connected to brake pedal F through level system L. The master cyclinder is connected to wheel cyclinder C through a tube T. The wheel cyclinder is having two position P1 and p2. These piston is connected to brake shoes S1 and S2 respectively . The spring S holds and S2 in position, fig. The similar system is conected to all the wheels of a vehicle.

WORKING. when the brake pedal is Pressed, the lever system operates. the piston P of the master Cylindir is  pushed inwards. there will be inceased pressure on Liquid at P , whiuch is  pascal,s law  . dew to it,P, and P2 move outwards. they force the brake shoes to move away from each other which in turn  press   against the inner rim  of the wheel and hence retard the Motion of the wheel, i.e., the brake becomes oprative.                                                                                                                                                                           when the pressure on the brake pedal is released, the brake shoes return to their normal  positions by the action of spring, which in turn forces the brake oil to return from wheel cylinder to master  cylinder.  

                Hydraulic lift.

hydraulic lift is an applicationof Pascal,s law . it is used to lift heavy Objects. it is a force multiplayer.                                                                                                                                                                         It consists of two cylinder C, and C2 connected to each other by a Pipe . the cylinders are fitted with water-tight frictionless pistons of different cross- sectional area.the Cylinders and the pipe contain a liquid. suppose a small force / is applied on the smaller piston of crosssectional area a. then

PRESSURE exerted on the liquid, P= f/A
                                                          

                                                         

According to pascal law,the same pressure P is also ansmitted to the larger piston of cross-sectional Area A
                             Force on larger piston is
F= P XA = F/A X A  = A/a X f
      As     A >a, therefore, F   >  f . 
hence by making the ratio A/ a large,  very heavy loads (like cars and trucks) can be lifted by the application of a small  force.

Elasticity: The property of body to regain its original configuration when deforming forces are removed is called relasticity.

Stress: The iternal restoring force acting for unit area for a deformed body is called stress.