Science and Engineering Key Concepts

• Study notes based on key concepts for science and engineering.

Scientific Method

• In the scientific method, variables are key.
• Independent variables are what is being added or changed, and there should only be one.
• Dependent variables are what is being measured in response to changes in the independent variable.
• Multiple trials are important to get more accurate results, reducing the impact of random errors.

Engineering Design Process

• The engineering design process involves a series of steps.
• First, identify the problem to be solved.
• Brainstorm multiple potential solutions.
• Plan and select the most promising solutions to develop.
• Create a prototype to test the chosen solution.
• Test and evaluate the prototype to see how well it works.
• Improve the design based on the test results.
• Communicate the results of the design process.

Manufacturing

• Manufacturing involves the proper use of tools.
• Screwdrivers are used to fasten screws and hold things together.
• Pliers are used to cut wires to the correct length.
• Wrenches are used to tighten nuts and bolts.
• Sanders are used to smooth surfaces.
• Tape measures are used to measure materials longer than one foot.
• Saws are used to cut materials to size.

Manufacturing Steps

• Manufacturing includes several key steps.
• Separating involves cutting down materials or removing excess material.
• Forming involves pressing or stretching materials into a desired shape.
• Molding involves using molds to create shapes.
• Conditioning involves changing material properties using chemicals.
• Assembling involves putting materials together to create the final product.
• Finishing involves last-minute tasks like painting or sanding before the product is sold.

Safety Precautions

• Safety precautions are critical in manufacturing.
• Wearing safety equipment like goggles, gloves, and lab coats protects workers.
• Never use power tools alone to prevent accidents when using heavy machinery.

Technological Systems

• Transportation systems include various modes of transport.
• Planes offer fast travel but are expensive.
• Helicopters fly slower but can land in many more locations.

Transportation Subsystems

• Transportation systems rely on several subsystems to function.
• The structural subsystem keeps the vehicle upright and able to move.
• The propulsion subsystem provides the power behind the vehicle, typically through a motor or engine.
• The control subsystem determines the vehicle's speed and direction.

Bridges

• Force of compression squeezes objects.
• Live loads on bridges include anything other than gravity, while dead loads are due to gravity.

Ecosystems

• Ecosystems consist of biotic and abiotic components.
• Biotic factors include all living things.
• Abiotic factors include all nonliving things, such as water and rocks.

Ecosystem Roles

• Organisms in ecosystems have specific roles.
• Producers make their own food through photosynthesis.
• Consumers get energy from eating other organisms.
• Scavengers eat dead animals and plants.
• Herbivores eat plants.
• Omnivores eat both plants and animals.
• Carnivores eat animals.
• Decomposers break down other organisms and enrich the soil.
• Keystone species are critical for an ecosystem's survival.

Energy Roles

• Producers have the most energy in an ecosystem.
• Tertiary consumers or higher have the least energy due to energy loss at each trophic level.

Food Web

• A food web represents the interactions between organisms in an ecosystem, showing who eats whom.
• A food chain is one pathway from a producer to a tertiary consumer.

Symbiotic Relationships

• Symbiotic relationships are interactions between species.
• Mutualism benefits both organisms involved.
• Commensalism benefits one organism while the other is unharmed.
• Parasitism benefits one organism and harms the other.

Biodiversity

• Biodiversity refers to the variety of species in an ecosystem.

Reproduction

• Reproduction can be sexual or asexual.
• Sexual reproduction involves two parents and results in more genetic diversity.
• Asexual reproduction involves one parent, producing offspring that are carbon copies of the parent.

Animal Behaviors

• Migration is the movement of species away from a location in search of better conditions.
• Reasons for migration include finding better climate, more food, water, or mates.
• Adaptations are ways a species changes to better its survival and ability to reproduce.
• Aggression is used to intimidate another animal or species when finding a mate or protecting food.
• Courtship is behavior used to attract mates.
• Territory is an area that an animal will protect for food, water, and offspring.
• Limiting factors include space, food, water, and other resources that restrict population growth.

Natural Resources/Human Impacts

• Renewable resources are replenished faster than they are used.
• Nonrenewable resources are used faster than they are created.
• Fossil fuels are cheap and powerful but cause pollution.
• Oils are cheap but also cause pollution.
• Only 3% of Earth's water is freshwater, and it is unevenly distributed.

Overpopulation

• Overpopulation occurs when a species grows beyond the resources available.
• Causes include pollution, lack of resources, and improvements in medications.

Waves and Electromagnetic Spectrum

• Wavelength is the distance between two wave crests.

• Frequency is the number of waves per second.

• Sound waves are longitudinal, moving back and forth.

• Sound waves move faster in solids due to closer particles.

• Sound waves cannot travel through a vacuum because it has no particles.

• Light waves are transverse, moving up and down.

• Refraction is the bending of light when it changes mediums.

• Reflection is light bouncing off surfaces.

Color

• the visible color you see from an object is the one being reflected (all other colors are absorbed).
• Black absorbs all colors.
• White reflects all colors.

Electromagnetic Spectrum

• The electromagnetic spectrum ranges from longest wavelength/lowest energy to shortest wavelength/most energy.
• The order is: radio waves, microwaves, infrared rays, visible light, UV rays, X-rays, and gamma rays.

Communication Systems

• Communication systems consist of several components.
• The source is where the message starts.
• The encoder converts the message into a transmittable form.
• The transmitter sends the message.
• The receiver gets the message.
• The decoder converts the message into a recognizable form.
• The destination is the final location of the message.

Universal Systems Model

• The universal systems model is used in engineering.
• Goal: wanted end result
• Input is what is put into the system.
• Process is what is done to get to the goal.
• Output is what is coming out of the system.
• Feedback can be positive or negative, reflecting thoughts about the result.