Higher Physics Lab Mechanics

#### Viscocity of Glycerine SK049

Exp-1 To determine the viscosity of glycerine.

• Solenoid for holding the ball.
• Transparent long glass tube.
• Strong heavy base.
• Digital timer.
• Stoke's law.
• Free fall.
• Electromagnet.
• Viscosity
• Terminal velocity.

Principle and Working:
A body moving in a fluid is acted upon by a frictional force in the opposite direction to its direction of travel. The magnitude of this force depends on the geometry of the body, velocity of the body, and the internal friction of the fluid. A measure for the internal friction is given by the dynamic viscosity η. For a sphere of radius r moving at velocity v in an infinitely extended fluid of dynamic viscosity η, the frictional force according to Stokes' law is given as:

F1=6.π.η.r.v

For a sphere moving along the axis of a cylinder of fluid of radius R, the frictional force is:

Where, ρ1 is the density of the fluid
ρ2 is the density of the sphere
g is the acceleration due to gravity

In the present setup, the viscosity of glycerine is found by allowing a steel ball to fall through a column of glycerine and measuring the time taken by the ball to cover a known distance. The steel ball is released using an electromagnet and simultaneously time is measured with a digital timer.

Contents:

 Cat. No. Item Name Qty. CH149 Intelligent timer 1 C7932 Glass tube 1 R4522 Ferrite magnet 3 SV190 Three Finger Clamp 2 SG100 ‘A’ base 1 C7050 Electromagnet 1 C9807 Stand rod 1 R2720 Steel ball 19 mm dia. 1 SB252 Glycerine 3 SW092 Boss-head 3 SN201 Flexible plug lead, 1m black 1 SN204 Flexible plug lead, 1m red 1 R3538 Steel ball 13mm dia. 1 R6061 Steel ball 15mm dia. 1 R2719 Steel ball 16mm dia. 1