FOSS Science
Water Planet
Study Guide
Investigation 1:
What is the Sun? The Sun is an average star, composed mostly of hydrogen (72) and helium (26%),
around which the other solar system bodies revolve. It is the star closest to the Earth.
What is the solar system? The solar system is the Sun and all the bodies that orbit it, including
planets and their moons, asteroids, and comets.
What is gravity? Gravity is the force of attraction between two objects; larger bodies, like the Sun,
have a greater force of gravity.
Why do planets travel around the Sun in circular paths? Gravity pulls on planets with a force that
changes their direction of travel from a straight line into a circle.
Compare and contrast asteroids and comets. Both orbit the sun and are smaller than planets.
Comets are rock mixed with ice while asteroids are just rock. Comets are farther from the Sun.
Investigation 2:
What is a variable? A variable is anything that you can change in an experiment that might affect
the outcome.
What variable might affect the number of cycles the pendulum makes in 15 seconds? Mass,
length, and starting position
Where have you seen a pendulum? In an old clock, at a museum, as a playground swing, in a
metronome
What variables made no difference in the number of swings? Mass and release position
Which variable did make a difference in the number of swings? Length
What is the relationship between the length of the pendulum and the number of swings it
makes in a unit of time? As the length of the pendulum increases, the number of swings decreases
What is a two-coordinate graph? A display of experimental data that shows a relationship between
an independent variable and a dependent variable
What is a prediction? A reasoned estimation of a future event based on context, data, pr
experience
Who was Galileo Galilei? Galileo was a man who changed the science of astronomy. He was the
1st to use a telescope to look at the solar system. He described features of Mars, Jupiter, and Saturn.
He made the 1st maps of the Moon’s surface and discovered satellites orbiting Jupiter.
Investigation 3:
What happens to a wet paper towel in an open cup? It becomes dry when the liquid evaporates
What happens to the water in a paper towel when it evaporates? It changes into water vapor and
moves into the air
Where does the most evaporation happen? At the warmest place
Where does the least evaporation happen? At the coolest place
How does the surface area of a volume of water affect evaporation? The larger the surface area
of a volume of water, the faster the water evaporates
Where does the water that forms on the outside of a cup of ice water come from? When water
vapor in the air touches a cool surface, it condenses into liquid
What causes frost to form? When water condenses on surfaces that are below the freezing point
for water (0ºC), the water freezes for form frost
How does temperature affect the amount of water vapor in the air? Warm air holds more water
vapor than cool air
Is warm air less dense or more dense than cold air? It is less dense
Investigation 4:
Is hot water denser or less dense than room-temperature water? Hot water is less dense than
room-temperature water. How do you know? It floats in room-temperature water.
Which is denser, hot water or cold water? Cold water is denser than hot water. How do you
know? It sinks in room temperature water while hot water floats on room temperature water.
What causes a convection current? A convection current occurs when the bottom of a mass of
fluid is heated. The warm water rises, cools, and then descends, creating a circular flow.
What happens when air is pushed in to a smaller space? Air molecules move closer together,
resulting in compressed air.
What causes atmospheric pressure? The weight of air
What is a heat sink? It is any material that can absorb heat. Water is a good heat sink because it
holds a lot of heat. Soil is not a good heat sink because it heats up and cools down quickly.
What happens when light is absorbed by matter? The matter gains energy and its temperature
goes up.
What variables affect how hot a material will get when the Sun shines on it? How hot a material
gets depends on the length of exposure, the intensity of the solar energy, the color of the material,
and the properties of the material.
Investigation 5:
Where is most of earth’s water found? In the oceans
What percent of the Earth’s water is fresh water? 3%
What percent of Earth’s surface is covered by water? 71%
Where is earth’s fresh water found? In the atmosphere, rivers, lakes, glaciers, groundwater,
animals, and plants
How is water recycled on earth? Water is redistributed and recycled by evaporation, condensation,
precipitation, and flow, a sequential process called the water cycle. There is only a certain amount of
water on Earth, no more is being made.
What is the sun’s role in weather? Solar energy is responsible for all weather and all changes of
weather. Solar energy heats earth’s surface, evaporates water, and drives wind
What is the ocean’s role in weather? Oceans are the main source of water vapor for precipitation.
Oceans also moderate temperatures along coastlines.
How are weather data obtained? Meteorologists use weather instruments on the ground,
radiosondes on balloons, and satellite images to obtain surface and atmospheric measurements of
weather variables.
What kinds of data are displayed on weather maps? Weather maps display atmospheric
pressure, weather fronts, and precipitation
What is most fresh water used for in California? Agriculture
What is a cause and effect of floods in California? Heavy rain or snow melts can cause flooding;
a result could be mudslides
What is the cause and effect of droughts in California? One result of too little rain is crop failure
What can result from Increased or decreased pressure on an air mass? Severe weather, wind,
fog, and precipitation
How does the Pacific Ocean affect the weather along the California coast? It creates mild
temperatures along the coast, is a source of water for rain and snow, and causes coastal breezes
due to uneven heating