Fluids and
Structures
Review
What is a fluid?
• A fluid is something that flows and can be a
liquid or gas. The two most common fluids
are water and air.
Name the three key
points to the Particle
Theory.
1. All matter is made up of particles.
2. Particles are in constant motion.
3. There are forces of attraction between
particles.
What is the
difference between
laminar and
turbulent flow?
• Laminar flow is the movement of a fluid in a
straight or almost straight line.
• Turbulent flow is the movement of a fluid in a
broken or choppy pattern.
What is viscosity?
• Viscosity is the resistance a fluid has to
flowing and movement.
Describe the
difference between a
thick and thin fluid.
• A thick fluid has a high viscosity and a slow
flow rate. A thin fluid has a low viscosity and a
high flow rate.
What is the formula
to calculate flow
rate?
• Flow rate = volume ÷ time
Order these substances from greatest to least
flow rate:
ketchup 1.5 mL/s
water 6.5 mL/s
corn syrup 0.3 mL/s
• The order for greatest to least flow rate is:
Water, ketchup and corn syrup
Describe the
difference between
weight and mass.
• Mass is the amount of matter in an object and
remains constant. Weight is a measurement
of the force of gravity pulling on the object. It
varies because gravity is different depending
on where you are in the universe.
What is the formula
to calculate density?
• Density = Mass ÷ Volume
What is the difference between buoyancy and
gravity?
• Buoyancy is the upward force that acts on an
object. Gravity is the downward force that
acts on an object.
Order these substances from least to most
dense:
Salt 2.16 g/mL
Silver 10.5 g/mL
Salt water 1.03 g/mL
Ice 0.92 g/mL
• The order from least to most dense is:
Ice, salt water, salt and silver
Name the three
types of buoyancy.
• The three types of buoyancy are positive
buoyancy, neutral buoyancy and negative
buoyancy.
What is the
difference between a
hydraulic and
pneumatic system?
• A hydraulic system is a confined system that
uses a liquid under a high pressure. A
pneumatic system is a confined system that
uses air under a high pressure.
List the six types of
simple machines.
1.
2.
3.
4.
5.
6.
Lever
Wheel and axel
Pulley
Screw
Inclined plane
Wedge
What is the purpose
of a machine?
• To make the work that we do more efficent.
Name the three
classes of levers.
• The three classes of levers are class 1, class 2
class 3.
What is the formula
to calculate
mechanical
advantage?
• Mechanical Advantage= load force ÷ effort
force
• What is the difference between a fixed and
moveable pulley?
• A fixed pulley changes the direction of the
force. A moveable pulley multiplies the force.
How does friction
relate to mechanical
advantage?
• Friction is a force that opposes movement. So
friction makes things less efficient reducing a
machine’s mechanical advantage.
Name the three
types of friction.
• The three types of friction are rolling, sliding
and fluid friction.
What is the formula
for calculating
pressure?
• Pressure = force ÷ area
What would be the
mechanical advantage
of a lever that can lift
80N with an effort of
only 20N?
• Mechanical Advantage = load force ÷ effort
force
• MA = 80N ÷ 20N
=4
How much pressure would be placed on a
surface with an area of 2m2 if an object weighing
500N were sitting on it?
• Pressure = Force ÷ Area
= 500N ÷ 2 m2
= 250 N/m2