IS 351

Represents a system for the purposes of analyzing and understanding that system

Can test to see if it meets expectations i.e. stream table

Explanatory ideas that are expressed in words and mathematics that are used instead of physical models because of time, distance and scale.

• Earth-centered model
• Ptolemy's model of the universe was geocentric. Planets orbited the Earth.

• Sun-Centered Model
• Copernicus' model of the universe was heliocentric. Planets orbit the sun.

Any system that can't be observed or touched directly and can't be completely understood. i.e. the Earth's core

Sorting once, then once again until each is in their own group. Teaches sorting and organizing.

Teaches students how to organize. Organization is used in decision making and contributes to the ease of remembering things.

A group that is divided into two sharply distinguished parts or classifications.

• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

Each year builds on the previous year

• Kilo - 10³ - King
• Deka - 10¹ - Died
• Deci - 10^-1 - Drinking
• Centi - 10^-2 - Chocolate
• Milli - 10^-3 - Milk

• Meter - to measure length
• Kilogram - to measure mass and/or weight
• Degree Celsius (Kelvin) - to measure temperature
• Second - to measure time

• Ampere - to measure electric current
• Candela - to measure luminous intensity
• Mole - to measure amount of substance

Liter - measures liquid

the amount of space an object takes up

side³

Length x Width x Heigth

Cubic cm = cm³ = cc = mL

• Use the displacement method and an overflow can
• Water Displacement Method - measure > put object in (just under water if floating) > measure > take difference

Bottom of curved surface

the property of a body that causes it to have weight in a gravitational field

Gravitational force exerted on an object by Earth

a metric unit of weight equal to 1/1000 of a kilogram

• the study of how size effects the relationship between weight, strength and surface
• think ants carrying 10x's their body weight

anything that has mass and volume, made up of atoms and molecules

• Chemical - you can see when the substance undergoes a chemical change, think rust
• Physical - can observe or measure, no change in composition

measure of how much matter is squeezed into a given space

Density = mass/volume = gram/cm³

Hot water is less dense and rises or floats on the more dense cool water. This movement of heat energy is by a natural convection.

• Why sink or float?
• Gravity - the mutual attraction between bodies that is proportional to the masses of the bodies and the distance between them
• Density - comparing 2 densities, take into account mass and volume
• Buoyancy - an upward force (push or pull) acting on all objects in fluids whether they are floating or submerged. Upward force is call buoyant force, which works against the downward force of gravity. As long as buoyant force is greater than downward pull of gravity the object will float.

The reason the diet drinks float and the regular drinks sink is directly related to the density of the liquid in each can. The difference between a can that floats and a can that sinks is the amount of sugar in the drink. Sugar is much more dense than water, and corn syrup is also heavier than water.

Measuring the density of a small piece of glass, metal, plastic and wood by the water displacement method, it was found that the higher the mass the higher the density. If the material has a density of less than 1 (pure water) it will float.

Testing the differences in the density of fresh water and salt water. The egg will sink in the fresh water and will float in the salt water. The egg's density is greater than the fresh water causing it to sink but the salt water's density is greater than the egg causing the egg to float.

The raisins will float to the top because CO₂ bubbles from the Alca-Seltzer attach to the raising and raise it up. When the raisins reach the top, the bubbles break and they sink. Raisins and CO₂ work as a system - the combination is less dense than water.

Demonstrate Archimedes principle and show that pressure works in all directions. The eye dropper fills up with water and sinks to the bottom when the bottle is squeezed. When the pressure is let go, the eye dropper releases the extra water and floats back to the top. The pressure on the bottle forces water up the eye dropper. Since the eye dropper becomes heavier it drops. Squeezing anywhere on the bottle produces the same results so it can be concluded that pressure works in all directions.

Every liquid has its own density, the liquid with the greatest density will layer at the bottom of the cup, and with every liquid poured in, a layer will form with its layer placement based on the liquid's density.

Density of Pure Water = 1.00

• Density of Pure Water = 1.00
• Density of Ice = 0.92
• Ice density is less than water density, therefore it floats

an upward force (push or pull) acting on all objects in fluids whether they are floating or submerged

Upward force of an object in liquid

The buoyant force exerted on an object in a fluid (gas or liquid) is equal to the weight of the fluid displaced by the object NOT the weight of the object itself.

• Why does the boat float when flat, but the ball of clay does not? The boat is a clay-air system.
• Density of the boat is less than the density of the water because of the air. Clay ball is greater than the buoyant force of the water.

• Alka-Seltzer Test (gas and buoyancy)
• Alka-Seltzer dissolved in water > bubbles will float on the CO₂ gas that the Alka-Seltzer produces