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Science Investigation for Fourth Grade Teachers Tips for Chaperones


·
Make sure you know the times of any special
demonstrations, movie, planetarium show, etc., your group is
due to attend. Arrive at least 5 minutes early for these
activities. (We do not allow groups to enter late if a movie or
planetarium show has started.)

·
Make sure your group stays together at all times.

·
Read through the Investigation materials. It is a good idea
to do this before you arrive. Read each investigation out loud
to your group as they explore the exhibit.

· Explore
at least three of the Investigation exhibits with
your group. You may wish to do more than three, however
realize that there are time constraints posed by lunchtime, films
and planetarium shows.

·
Always discuss each exhibit with your group. Talking
about what they saw or did reinforces their learning.





Science Investigation
for Fourth Grade
Teachers


Do you wonder how electric current travels, or how magnets
can generate electricity? Do you know how water can change
the surface of the earth? In this Investigation you can explore
these questions and discover lots of things
a fourth grader needs to know!

Are you ready? Lets go!



August 2005 Build a Circuit
When you flip a light switch on and off, you are closing and
opening a circuit. A circuit is the path that electricity follows.
For electrical current to travel, the circuit must be closed.
When you flip the switch on, the circuit is closed and the lights
come on. When you flip the light switch off, you are opening the
circuit and the lights turn off.

Where to go: Build a Circuit (1
st
Floor, Many Hands Make a
Home)

What to do: Arrange two blocks with wire and the block with
the light in a line, going from + to - on the power supply.
You have made a series circuit!

Insert the switch in the circuit. Use the switch to close and
open the circuit.

Next, insert the current meter. This meter tells you how much
current is left after the light draws some out of the circuit.

How much energy is left after the light draws from the circuit?
_____________milliamperes

Insert the fan next to the light and watch the meter. What does
it read now? _____________

Did you know?
A series circuit allows electricity to follow only one path. The
loads (for example, a light or a fan) in a series circuit must share
the available power. In other words, each load in a series circuit
will use up some of the electricity, leaving less for the next load
in the circuit. This means that the light, heat, or sound that is
given off will be reduced.
Desert Water
Until the completion of the Roosevelt Dam in 1911, Phoenix
was periodically flooded by the Salt River. The Salt River Project
(SRP) built the dam to store water for times of drought and to
protect the farmland from floods in wet years.

Where to go: Stream Table (World Around You, 3
rd
floor), then
Aerial Photo of Phoenix (Many Hands Make A Home, 1st floor)

What to do: Start at the stream table. Use the paddles and try to
create these kinds of river formations in the sand:

Meander rounded, S-shaped bend or loop in a river
River fork a point along a river where a second river
branches off from the first
Sandbar shallow deposit of sand found on the inside of a
river bend where the currents are slower.

Now go downstairs and look at the aerial photo of the Phoenix
Valley. Find the Salt River as it cuts across Phoenix from
northeast to southwest (N is up, W is left).

Can you find examples of the 3 river formations in this real river
system?

Now find 3 other kinds of water features on this map: canals,
lakes, and swimming pools. Which of these are man-made?
Where do you think the water comes from to fill these?

Did you know?
Many of the canals of historic Phoenix were first dug by the
prehistoric Hohokam Indians over100 years ago.


Magnetic Attractions
Electromagnets have a core of metal inside a coil of wire that
carries an electric current. The electricity in the coil creates a
magnetic field. The properties of the magnetic field change if the
electric current is changed.


Where to go: Current Attractions (3rd floor, Fab Lab)

What to do: Take the brown glove and place it on one of the
metal tabletops. Each tabletop has a field of four electromagnets.

Use the dials marked amplitude, phase, and frequency to change
the current in the electromagnet.

Watch for matching changes in the motion of the glove over the
electromagnets!


Can you make the glove fingers thump on the tabletop?

Which dial controls the speed of the movement?


Experiment with other materials at this station to see how
electrical current affects their motions.

Did you know?
Electromagnetic waves were first described by observing the
relationship between magnets and electricity. The waves that
carry radio and television, microwaves, infrared, visible light,
ultra-violet, x-rays and gamma rays all belong to the family of
electromagnetic waves. Frequency, amplitude, and phase are
used to describe these waves and how they move.

Magnets and Electricity
Magnetism is closely related to electricity. If you move a wire
near a magnet, it will produce a current in the wire. This is how
a simple generator produces electricity.

Where to go: Generators (3
rd
floor, Fab Lab)

What to do: Find the switches on the exhibit panel that turn the
radio and the video monitor on and off. Switch the radio on and
the monitor off.

Turn the large crank handle until you hear sound from the
radio.

Now switch the radio off and the video monitor on.

Crank the generator again.

Which needed more of your energy to turn on, the radio or the
video monitor?

Can you make them both run at the same time?

Explore the generators in other exhibits in the Science Center.

Did you know?
When you turn the handle, you are using kinetic energy (energy
of motion) to make electric energy through the generator. The
handle spins the shaft, which goes inside the metal casing of the
generator. Inside, the shaft is wrapped with copper wire. The
case of the generator is lined with magnets.
Magnet + copper wire + motion = electricity!
Wheres the Water?
Freshwater makes up only a small amount of the total water on
the earth about 3 %. Most of the freshwater is tied up in
glaciers and ice caps. About one-third (30%) of the earths
freshwater is groundwater. Less than .5% of the earths total
freshwater is found on the surface in lakes, rivers and swamps!

Where to go: Water Table (3
rd
floor, World Around You)

What to do: Turn the wheel and watch the column of lights drill
a well through typical Arizona sediments.

How many layers do you go through before you reach the
aquifer (where water fills all of the spaces in sand, clay or
gravel)?_______________

What forms the upper surface of the aquifer?

water table
underground lake

lawns


What kind of sediment is at the bottom of this well?

____________

Did you know?
In Arizona, most of the water that recharges aquifers comes
from streams fed by mountain runoff. Arizona also gets water
from the Central Arizona Project (CAP), which brings water
over 300 miles from the Colorado River. CAP water is treated
and sent to houses, or put in basins, like artificial lakes, where it
seeps down into the ground and slowly recharges the aquifer.
More recharge comes from storm water and treated sewage.

Copper Conductivity
Some materials are better conductors than others electricity
can easily flow through them. An insulator does not allow the
free flow of electrical current. Conductors are used in circuits
to let electricity flow; insulators are used to protect materials,
and people, from electrical current.

Where to go: Do You Conduct? (3
rd
Floor, World Around You)

What to do: Discover which materials are conductors by placing
each of the five containers into the holder and watching the dial.
When the dial moves to the right, electric current is moving
through the material it is a conductor!

Circle the materials that are conductors:

wood
copper
rubber
band


steel nail
magnet


How are the conductors all alike?


Did you know?
Copper has been an important mineral in Arizona since
prehistoric times. Many early explorers and settlers came to this
state because of its copper deposits. Copper mining was so
important in the 1970s, that there was a saying about Arizona:
Copper is king. More than half of our countrys copper still
comes from Arizona's copper mines.