Viscosity is a measure of how quickly a fluid flows, determined by internal friction between particles. Fluids with greater friction between particles, like molasses or ketchup, have higher viscosity and flow more slowly than those with less friction, like water or juice. The ramp test can compare viscosities by timing how long it takes fluids to flow down a ramp, and viscosity can be investigated by testing fluids at different temperatures - viscosity decreases as temperature increases because particles slide and roll more easily with added energy.

1. Viscosity

2. Viscosity
Viscosity: is a property of how quickly a fluid flows. It is
determined by internal resistance or friction.

3. Viscosity
PMOM (Particle Model of Matter): Recall that
liquid particles slide around and roll over each other and
gas particles move more evenly and easily.
The greater the friction (or rubbing) between particles in
a fluid, the greater the viscosity (slower it will flow).

4. Viscosity
High Viscosity = flows slowly
examples: molasses, ketchup
Low Viscosity = flows quickly or easily
examples: water, juice

5. Viscosity
The ramp test: tests viscosity by pouring a
fluid down a ramp and timing how long it
takes to reach the bottom.
This enables you to compare viscosities of
different fluids. You can also investigate
the effect of temperature on the viscosity
of a fluid. First pour the fluid down
at room temperature. Then either cool or
warm the fluid and test it again.

6. Viscosity & Temperature
As the temperature of a liquid increases, its viscosity decreases.
The reverse is also true.
P.M.O.M and Change of Viscosity:
Liquids have particles that slide and roll. As energy or heat is
added, the particles slide and roll more quickly. Therefore the
fluid flows more readily or has a decreased viscosity. The reverse
is also true.