Natural Resources
A community relies heavily on oil and sand. Predict the long-term impact on resource availability and explain why.
Oil and sand are nonrenewable; overuse will deplete them faster than they can be replenished, causing shortages.
Two rocks look identical, but one sinks in water while the other floats. What property explains this difference?
Density, a physical property, determines whether an object floats or sinks without changing its identity.
Why does water boil at a lower temperature on a high mountain compared to sea level?
Air pressure is lower at high elevations, so particles require less energy to overcome pressure and enter the gas phase.
An engineer must design a bridge that is light but can hold heavy trucks. Explain a possible tradeoff in this design.
Reducing weight may lower strength; increasing strength may make it heavier, so one feature is sacrificed to improve another.
A designer wants to create a playground slide using wood and metal. They notice that metal heats up faster in the sun than wood. Using your knowledge of particle motion and properties of matter, explain why the engineer might choose wood over metal for safety.
Metal particles transfer thermal energy faster due to their structure, making it hotter and unsafe. Wood has lower thermal conductivity, so it stays cooler, reducing the risk of burns.
If humans replaced coal with wind energy in a city, what would be one major societal and environmental effect?
Reduced air pollution (positive for society and ecosystems) and sustainable energy supply due to renewable resource.
Wood burns into ash and gas. Explain how this demonstrates a chemical property and why it’s different from a physical property.
Burning changes the wood’s identity (chemical change), unlike physical changes that only alter appearance.
How does freezing a liquid affect the motion and arrangement of its particles?
Particles lose energy, slow down, and arrange in a fixed pattern forming a solid.
A bridge must hold heavy vehicles without breaking. The engineer tests different materials to see which can withstand the most stretching force before breaking. Which property are they measuring, and why is it important for the design?
They are measuring tensile strength, which is important because it indicates how much force the material can withstand before breaking, ensuring the bridge will be safe for vehicles.
A community wants to build a water filtration system using renewable resources. How could overuse of renewable resources still harm ecosystems, and what strategies could engineers use to design a sustainable system?
Even renewable resources, if overused, can reduce biodiversity or disrupt habitats. Engineers could design iterative systems that recycle water, use minimal resources, and balance efficiency with environmental impact.
Water is essential for all living things. How might overharvesting water affect biodiversity in an ecosystem?
Reducing water can harm plants and animals, lowering biodiversity and disrupting ecosystem balance.
Explain why light and heat are not matter, even though they carry energy.
They have no mass and do not occupy space, so they don’t meet the definition of matter.
Evaporation occurs over a wide temperature range while boiling occurs at a fixed temperature. How does particle motion explain this difference?
Evaporation only involves fast-moving surface particles; boiling involves all particles reaching sufficient energy to change state.
Engineers are asked to design a wind turbine in a community where wind speed is inconsistent. Using your understanding of iterative testing, describe how engineers might improve the design.
Engineers could test different blade shapes, sizes, or angles multiple times, analyze the energy output at different wind speeds, and refine the turbine design based on the test results to maximize efficiency.
Engineers are designing a lightweight bridge for a park. They can use either one strong but heavy material or several weaker but light materials. Using tradeoffs, criteria, and tensile strength, explain how they might decide the best design.
They must weigh strength versus weight. Iterative testing could reveal if lighter materials in combination can meet safety criteria without making the bridge too heavy, showing the tradeoff between material strength and total weight.
A natural resource’s life cycle includes collection, production, and use. How could consumer preferences speed up the depletion of a nonrenewable resource?
Increased demand leads to faster extraction and use, causing nonrenewable resources to run out sooner.
How would adding thermal energy to ice affect particle motion and the state of matter?
Particles move faster; ice melts into liquid as energy overcomes attractive forces.
Condensation occurs when a gas becomes a liquid. Using particle motion, explain why this happens.
Gas particles lose kinetic energy, slow down, and attractive forces pull them into a closer, liquid arrangement.
An engineer must design a container to store oil safely, but the container should also be lightweight for transport. Identify two constraints and one tradeoff they might face.
Constraints: (1) Must prevent leaks, (2) Must be lightweight.
Tradeoff: Making the container heavier could make it stronger and safer, but lighter materials might risk spills. The engineer must balance strength and weight.
During a science experiment, students heat water in a sealed container at high elevation. Predict how air pressure affects the boiling point and explain why particle motion and energy distribution matter in this situation.
Lower air pressure at high elevation reduces the boiling point because particles need less energy to overcome the weaker atmospheric pressure. Faster-moving particles allow the liquid to transition to gas at lower temperatures.
Explain why sunlight and wind are considered renewable, but oil is not, using their natural replenishment rates.
Sunlight and wind are continually available in short time spans, while oil takes millions of years to form and cannot be replenished quickly.
A substance’s mass stays the same when it melts, but volume may change. How does this illustrate a difference between mass and volume as properties?
Mass is constant (amount of matter), but volume can change as particles spread in a liquid state.
A solid melts into a liquid at its melting point. How would this process differ if the solid were heated unevenly?
Parts of the solid with more energy melt first, showing that particle motion and energy distribution determine local state changes
Imagine you are designing a water bottle that keeps liquids cold. You must consider the properties of matter (like heat transfer). How could understanding particle motion help you choose materials?
Materials with particles that are poor conductors of heat will reduce energy transfer, keeping liquids cold longer. Engineers can use this knowledge to select insulating materials like certain plastics or double-walled metal.
A company wants to minimize environmental impact while producing a wooden product. Using the product life cycle, properties of matter, and engineering design principles, propose one innovation that could achieve this and explain why it works.
They could use a recycled composite material or redesign the product to use less wood. By testing prototypes iteratively, they can ensure durability while reducing resource use, minimizing ecosystem disruption, and balancing cost and functionality.