Name: 

Water is less dense than ice.

Pressure is calculated by multiplying force by area.

When a force of 80 N is exerted on a surface area of 10 m², the pressure is 8 Pa.

The pneumatic system is a confined, pressurized system that uses moving liquids.

A ballast acts as weight and alters density to help a vessel travel at the appropriate level in a fluid.

Hydraulic systems use gases under pressure to move many things.

The lungs operate as a pneumatic system because they move air in and out of your body.

Resistance to aerodynamic flow is referred to as ____________________.

When we refer to the thickness or thinness of a liquid, we are really describing its ____________________.

Buoyancy is a force and is measured in ____________________.

Helium gas will float on top of ____________________.

Snowshoes distribute a person’s weight over a ____________________ area than a pair of shoes.

The weight of the air pushing down on itself and on Earth’s surface is known as _________________________.

Hydraulic and pneumatic devices are useful because they ____________________ forces to perform tasks that cannot easily be performed by people.     

Fish control their depth in water by using ____________________ that contain air.

____________________ control the flow of a fluid.

The heart is to a hydraulic system, as the lungs are to a ____________________ system.

When heat is removed from a fluid, which of the following is slowed down?

a.	density	c.	viscosity
b.	particles	d.	temperature

A force can be defined as

a.	a push or pull that can cause a change in motion
b.	gravity
c.	kinetic molecular theory
d.	an up and down or side to side motion

A reservoir of compressed air

a.	usually supplies the power in a hydraulic system
b.	usually supplies the power in a pneumatic system
c.	usually supplies the power in both systems
d.	usually supplies the power to the reservoir

Pressure is defined as the force per unit of area, and can be calculated using the following formula:

a.	P force/area	c.	P area/weight
b.	P area/force	d.	P force area

If the force of gravity on a diver is 650 N, what should the buoyant force be if the diver wants to remain at a certain depth in the sea?

a.	zero	c.	equal to 650 N
b.	less than 650 N	d.	greater than 650 N

An exotic species that is introduced to a new environment may

a.	add to the varieties the area already has	c.	simply die out
b.	compete with native species for food	d.	none of the above

For the lungs to exhale air, the pressure inside the lungs must be __________ the pressure outside.

a.	equal to	c.	less than
b.	greater than	d.	none of these

If you had two substances that looked identical, what would be one way to identify them? Using the knowledge you have just learned, explain your thinking.

In one or two sentences, explain the term cohesion.

Write one or two sentences describing the difference between mass and volume.

A hydraulic system uses two cylinders of different surface areas. The larger cylinder has 15 times more area than the smaller one. Which cylinder can push with greater force? By how many times?

If the temperature of a fluid is held constant, how is the pressure related to the volume of the fluid?

What makes up a pneumatic system?

A fish uses a swim bladder to control its depth in water. Describe what a fish could do to descend to a deeper level.