Viscosity and Temperature
Section 3.1 p. 39
Learning Outcome
• investigate
and compare fluids, based on their
viscosity and flow rate, and describe the effects of
temperature change on liquid flow
Viscosity
• How quickly a fluid can flow is called viscosity
• It is determined by a fluids internal resistance or friction that keeps it from
flowing
• The greater the friction or rubbing between particles in any fluid, the higher
the viscosity.
• Fluids with high viscosity do not flow easily as fluids with a low
viscosity
Measuring Viscosity with the Ramp Test
• Testing Viscosity of 4 Fluids at different temperatures
• Task
• To test the viscosity of shampoo, vegetable oil, pancake syrup, engine oil at different room
temperatures
• Procedure
• Split up into groups (each group will perform the ramp test on the same fluids but at
different temperatures)
• One person will need to hold the ramp
• One to time the fluids
• Two to pour the fluids
• Make a data chart to record your results, as well as the other groups data
• Decide which substance has the highest viscosity (flows the least)
• Does heat affect all of the substances fairly even? Why or why not
Understanding how Temp affects Viscosity
• We know that as thermal energy is added to particles, they will be
able to move and slide around more freely
• Thus the fluid flows more freely (less viscous)
• When thermal energy is removed, particles move slower, and
frictional forces increase
• Causing fluids to flow slower (more viscous)
Fluids from the Environment
• Albertans use to use the thick Bitumen of the
oil sands to seal their canoes
• The bitumen is incredibly viscous and would make
an excellent sealer
• Aboriginals also use to use tree sap to make
glue for building canoes
• Motor Oils use different viscosity for different
types of weather
• i.e. higher W number means more viscous
• 10W-40 is quite viscous and good in the summer time
• 5W-40 is less viscous and easier for vehicles to use in the
summer time