Lesson 2.4: Models and Systems

​Science Root of the Day:

DO NOW: Write what you think the example words mean in your lab manual.

Extra Credit: Find three additional words that use this root and write them and their definition in your lab manual (6 Points Max)

​Lesson 2.4: Models and Systems

Multiple Choice

A(n) __________ is a data point that is clearly not part of a graph's trend

• Outlier

• Independent

• Pie chart

• Average

Multiple Choice

The closeness of a measurement to its true value is its

• Average

• Accuracy

• Precision

• Estimate

Multiple Choice

The official SI unit for temperature is ____________________.

• Farenheit

• Celsius

• Kelvin

Lesson Objectives

• Explain how models are used in science

• Describe different types of systems

  • Identify parts that are found in all systems

• Examine Models of systems and compare them to the actual system

How do Scientists Use Models

• A model is any representation of an object or process

  • Examples: globes, posters, sculptures, computer programs

    • Not all models are physical

  • Allow Scientists to test ideas about things they can't observe directly

    • Things that are very small or very large

  • Used to represent Systems

Characteristics of Systems

• A system is a group of parts that work together to carry out a function

  • Many things exist as systems

    • bikes, toasters, flashlights

Characteristics of Systems

• All systems have at least one input, one process, and one output​

  • Input: a material/energy that goes into a system

  • Process: the action or series of actions that happen in a system

  • Output: the material or energy that comes out of the system

    • Feedback: Output that changes a system in someway

      • Example: Your thermostat tells the furnace to heat the house to a certain temperature. Once it hits that temperature, the furnace shuts off

Understanding Systems

• Example 1: A toaster

  • Input: electricity & Bread

  • Process: Bread is heated

  • Output: Hot toast

• Example 2: Bike Pump

  • Inputs: Air​ and energy

  • Process: Air pressure is increased

  • Output: Compressed air

Match

A car is a type of system. Match the input, process, and output.

• Input

• Process

• Output

Gasoline

Fuel is burned and moves the engine

Carbon dioxide

• Gasoline

• Fuel is burned and moves the engine

• Carbon dioxide

Multiple Choice

A _____ is a group of parts that work together to preform a function.

• model

• system

• input

• output

• feedback

Multiple Choice

A _____ is something scientists use to test ideas about things they cannot observe directly

• model

• system

• input

• output

• feedback

How do Models help Scientists understand systems?

• Observing inputs and outputs in a system can be easy, but seeing the processes can be difficult

• Scientists build models to represent a process

  • Test different processes to see if the inputs/outputs of their models match the inputs/outputs in the real world

  • Models can help predict changes in a system

  • Example: The Everglades

    • https://www.smithsonianmag.com/videos/category/science/florida-everglades-restoring-the-wetlands/

Modeling Simple & Complex Systems

• Some Systems are simple with only one or two inputs or outputs, but others are much more complex

  • Example: Weather systems

• In order to study complex systems, scientists ofte​n break them down into smaller, more specific parts of the systems

Multiple Select

Which of the boxes in the diagram show inputs into the system of the Mercury Cycle?

• Mercury released in burning of wastes and fossil fuels

• Mercury released from rocks and soil

• Mercury dissolves

• Small organisms eat sediment

• High concentration of Mercury in Fish

Multiple Select

Which of the boxes in the diagram show processes in the system of the Mercury Cycle?

• Mercury sinks to the bottom

• Fish eat organisms

• Mercury dissolves

• Small organisms eat sediment

• High concentration of Mercury in Fish

Multiple Choice

Which of the boxes in the diagram show outputs in the system of the Mercury Cycle?

• Mercury sinks to the bottom

• Fish eat organisms

• Mercury dissolves

• Small organisms eat sediment

• High concentration of Mercury in Fish

Testing Assumptions

• When a scientist constructs a model of a system, they begin with certain assumptions

  • It is important ​to check those assumptions by comparing the inputs and outputs of the natural world to those in the model

    • if they match, those assumptions are presumed correct

    • if they don't match, scientists must change their assumptions and adjust their models

  • Some assumptions are used to simplify complex models

    • example: Food webs can be simplified to make it easier to study interactions between only two organisms

Multiple Choice

Scientists test their ideas about things they cannot observe directly by building

• models

• theories

• systems

• evidence

Multiple Choice

Scientists check ______ by comparing the inputs and outputs of a model to the inputs of a natural system.

• assumptions

• bias

• processes

• feedback

Open Ended

Give three examples of models you would use to explain something in your everyday life. Explain one way they are different from the actual system and one way they are similar.