Untitled Flashcards Set

Science and Engineering Basics

• Science is the study of phenomena and seeks to understand how natural and designed systems work.
  
  

• Scientific discoveries improve or change our understanding of natural events and systems.
  
  

• Engineering is the systematic process of solving problems using designed solutions.
  
  

• Engineers create technology, which includes tools, processes, and systems designed to solve problems.
  
  

• The designed world is everything in our environment made by humans. It exists within the natural world.
  
  

• We depend on both natural and designed systems in our daily lives.
  
  

Technology and Society

• Technology helps meet basic needs like food, shelter, and clothing.
  
  

• It also affects how we communicate, travel, and play.
  
  

• Bicycles are an example of how technology evolves due to safety, ease of use, and social changes.
  
  

• Technology can improve lives (e.g., medical advancements like insulin and organ transplants).
  
  

Systems Thinking

• A system is a group of interacting parts working together.
  
  

• Systems can be natural or engineered.
  
  

• Studying systems helps scientists and engineers understand how energy and matter flow.
  
  

• All systems have:
  
  

  • Components (parts)
    
    

  • Inputs (what enters)
    
    

  • Outputs (what leaves)
    
    

  • Boundaries (define what is in/out of the system)
    
    

  • Feedback (when outputs affect future inputs)
    
    

• Systems are connected—they don’t exist in isolation.
  
  

Engineering Design Process

• Engineers begin by clearly defining a problem (not necessarily something that is "wrong").
  
  

• The design problem must describe what the solution needs to do.
  
  

• The engineering design process includes:
  
  

  1. Defining the problem
     
     

  2. Identifying criteria and constraints
     
     

  3. Designing possible solutions
     
     

  4. Testing solutions
     
     

  5. Redesigning as needed
     
     

• Criteria are the features a solution must have (what it should do, how it works, who needs it).
  
  

• Constraints are limits engineers must work within (cost, time, materials, laws, etc.).
  
  

• Simple engineering problems (like a thumbtack) and complex problems (like a subway system) both use this process.
  
  

Energy Concepts

Kinetic Energy

• Kinetic energy is the energy of motion.
  
  

• Depends on:
  
  

  • Mass (more mass = more kinetic energy)
    
    

  • Speed (faster = more kinetic energy)
    
    

• Formula: KE increases with the square of velocity.
  
  

Potential Energy

• Potential energy is stored energy due to position or condition.
  
  

• Gravitational potential energy increases with height above Earth's surface.
  
  

• Examples:
  
  

  • A ball at the top of a hill has more potential energy than at the bottom.
    
    

  • Water at the top of a waterfall has high potential energy.
    
    

Law of Conservation of Energy

• Energy cannot be created or destroyed, only transferred or transformed.
  
  

• The total energy in a system stays the same unless added or removed.
  
  

Energy Transfer

• When objects collide, energy is transferred from one to another.
  
  

• Example: A bowler gives energy to a bowling ball → the ball hits the pin → energy is transferred to the pin.
  
  

• Sound from a collision is evidence of energy transfer.
  
  

Types of Energy

• Kinetic energy types:
  
  

  • Thermal
    
    

  • Sound
    
    

  • Electromagnetic
    
    

  • Electrical
    
    

• Potential energy types:
  
  

  • Gravitational
    
    

  • Elastic
    
    

  • Chemical
    
    

  • Nuclear
    
    

• All energy is measured in joules (J).
  
  

Mechanical Energy

• Mechanical energy is the sum of kinetic and potential energy in an object or system.
  
  

• It can be:
  
  

  • All potential
    
    

  • All kinetic
    
    

  • A mix of both
    
    

• Used to do work on other objects (e.g., hammering a nail).

🔄 Life Cycle of Products and Natural Resources

• Natural resources are used in the first stage of a product’s life cycle.
  
  

• All stages of a product’s life cycle affect natural resource use.
  
  

• Resources may be used to make products or to power production (as energy).
  
  

• Reusing and recycling products reduces the need for new natural resources.
  
  

• Scarce resources may lead to the creation of alternative materials.
  
  

🧲 Magnets and Magnetic Force

• Magnets attract materials that contain iron, nickel, or cobalt.
  
  

• All magnets have north and south poles that can attract or repel.
  
  

• Magnetic force is a non-contact force (acts at a distance).
  
  

• Magnetic force strength varies with distance and materials affected.
  
  

⚡ Electric Charge and Static Electricity

• Electric charge is a property of matter; all electricity comes from it.
  
  

• Charges can be positive (+) or negative (−).
  
  

• Most objects are neutral (equal + and − charges).
  
  

• Static electricity is caused by imbalanced charges.
  
  

• A spark occurs when charges move suddenly, like when touching a doorknob.
  
  

⚡ Electric Force

• Electric force is the push or pull between charged objects.
  
  

• Like gravity and magnetism, it acts at a distance.
  
  

• It can make socks stick together or balloons stick to walls.
  
  

🌀 Fields and Field Lines

• A field is an area where a force acts without touching.
  
  

• Field lines model force direction and strength.
  
  

• Closer field lines = stronger force.
  
  

• Gravitational fields pull objects toward any object with mass.
  
  

• The sun’s gravitational field extends across the solar system.
  
  

🧪 Physical and Chemical Properties

Physical Properties:

• Observed without changing the material.
  
  

• Examples: color, shape, transparency, hardness, mass, volume, density.
  
  

• Help determine if something floats or sinks or how it reacts to force.
  
  

Chemical Properties:

• Describe how a substance reacts chemically.
  
  

• Examples: flammability (ability to burn), reactivity (like rusting).
  
  

• Flammable: paper, wood, cotton. Not flammable: glass, steel.
  
  

🔬 Pure Substances and Mixtures

• A pure substance has only one type of basic particle (element or compound).
  
  

• Most materials are mixtures (like rocks, petroleum, wood).
  
  

• Cast iron is a mixture of iron and other elements.
  
  

🌳 Natural Resources

• Natural resources = useful materials from nature (e.g., wood, coal, sunlight).
  
  

• Can be living (plants, animals) or nonliving (rocks, water, metals).
  
  

• Used for food, fuel, building, and manufacturing.
  
  

🧱 Properties and Chemical Makeup of Natural Resources

• Used for physical traits (like copper’s conductivity or granite’s hardness).
  
  

• Used for chemical traits (like coal’s flammability).
  
  

• Natural resources may be elements, compounds, or mixtures.
  
  

• Many dyes once came from plants, like indigo.
  
  

🧬 Synthetic Materials

• Synthetic materials are human-made, often using natural substances.
  
  

• Examples: plastic, glass, ceramics, medicines, fuels (like biodiesel).
  
  

• Most bike parts are synthetic, not natural.
  
  

🧩 Polymers and Composites

• Polymers = long chains of repeating molecules (like polyethylene).
  
  

• Plastics are polymers.
  
  

Composites are made by combining 2+ materials (e.g., fiberglass, dental fillings).