Engineering Design Process: Problem Solving

• Engineering Design Process is a process to solve issues.

Engineering Design Process

• Identify the core problem.
• Gather background information on the problem.
• Define the requirements that the solution must meet in order to solve the problem.
• Research existing solutions to see if there are opportunities to improve.
• Brainstorm new solutions to the problem.
• Develop solutions and create initial concepts and models.
• Evaluate the feasibility of the concepts.
• Build a prototype.
• Test the prototype to see how it performs.
• Collect data and evaluate against goals.
• Refine and iterate to improve the design based on tests.
• Continuously improve solution until requirements are met.
• Communicate results to stakeholders.

Engineering vs Science

• Science's aim is to understand the natural world.
• Science seeks to discover underlying principles, laws, and phenomena such as studying the behavior of gases in various conditions.
• Engineering applies scientific principles to solve real-world problems.
• Engineering focuses on creating solutions, structures, or systems such as designing a more efficient engine.

Hypothesis and Experiment Design

• A hypothesis is a testable prediction about the outcome of an experiment.
• A null hypothesis (H0) assumes no effect or relationship.
• Null Hypothesis example: increasing temperature has no effect on the rate of reaction.

Experiment Design

• Independent Variable: This is changed during the experiment.
• Dependent Variable: This is measured.
• Control Variables: These stay constant.
• Sample Size: Should be large enough for accuracy.
• Procedure: Follow clear steps to conduct the experiment.
• Collect Data: Record observations and measurements.
• Analyze Results: Compare with the hypothesis and draw conclusions.
• Conclusion: Determine whether the hypothesis is supported.

States of Matter and Changes

• Solid turns to liquid (Melting) when energy is added, molecules move more freely.
• Liquid turns to gas (Evaporation) when molecules gain enough energy to overcome the liquid's surface tension.
• Gas turns to liquid (Condensation) when molecules lose energy and bond together.
• Liquid turns to solid (Freezing) when molecules lose energy and slow down.
• Gas turns to solid (Deposition) when gas turns directly into a solid without becoming liquid.
• Solid turns to gas (Sublimation) when a solid directly turns into a gas without becoming a liquid.

Weather patterns/Precipitation

• Water vapor in the air condenses into liquid or solid forms due to cooling (rain, snow, hail).
• Clouds form as the air cools and moisture condenses.
• Precipitation occurs when the condensed water droplets become too heavy to remain suspended in the cloud.

Wind

• Air moves from high-pressure areas to low-pressure areas.
• The Earth's rotation (Coriolis effect) and uneven heating of Earth's surface create wind patterns.
• Wind is affected by geographic features like mountains and valleys.

Air Currents

• Uneven heating of the Earth's surface creates differences in temperature and pressure and causes air currents.
• Warm air rises creating lower pressure.
• Cool air moves in to replace it, creating higher pressure.

Global Wind Patterns

• Trade Winds: Move from east to west in the tropics.
• Westerlies: Move from west to east in the mid-latitudes.
• Polar Easterlies: Move from east to west in polar regions.

Convection Cells

• Warm air rises at the equator, cools, and sinks at the poles.
• Convection cells create air circulation patterns (Hadley, Ferrel, and Polar cells).

Thunderstorm Formation

• Warm, moist air rises from the Earth's surface due to the sun's heating.
• Air cools and condenses, forming clouds.
• This process builds electrical charges within the cloud.
• Lightning occurs when the charges equalize.
• Thunder is the sound produced by the rapidly heated air.

Ocean Currents

• Wind drives surface currents.
• Temperature differences: Cold water sinks and warm water rises, helping create deep ocean currents.
• Earth's rotation (Coriolis effect) influences the direction of ocean currents.
• Salinity: Saltwater is denser, so it sinks, influencing vertical currents.

Important Currents

• Gulf Stream: Warm current from the Gulf of Mexico to the North Atlantic.
• California Current: Cold current along the western coast of North America.

Temperature Affects Pressure

• Temperature and pressure are related in gases.
• As Temperature increases molecules move faster and spread out.
• An increase in temperature increases the pressure if the volume is constant.
• Boyle’s Law: At constant temperature, pressure and volume are inversely proportional.
• Charles’s Law: At constant pressure, volume and temperature are directly proportional.

Bernoulli's Principle

• As the speed of a fluid increases, its pressure decreases.
• Airplane wings, the faster air over the top of the wing lowers pressure, creating lift, showing Bernoulli's Principle in action.
• Venturi Effect, fluid speeds up in a narrow passage, causing pressure to drop, showing Bernoulli's Principle in action.

Percent of Gases in the Atmosphere

• Nitrogen (N₂): ~78%
• Oxygen (O₂): ~21%
• Argon (Ar): ~0.93%
• Carbon Dioxide (CO₂): ~0.04%
• Other Gases: Trace amounts (e.g., neon, helium).

Layers of the Atmosphere Properties

• Troposphere: Closest to Earth’s surface, weather occurs here, and temperature decreases with altitude.
• Stratosphere: Contains the ozone layer, which absorbs UV radiation, and temperature increases with altitude.
• Mesosphere: Coldest layer where meteors burn up.
• Thermosphere: Very hot, with temperatures rising sharply, contains ionized gases (auroras).
• Exosphere: Outermost layer with very thin air, where particles escape into space.