Why do shadows change length throughout the day?
Because Earth rotates, changing the Sun’s angle in the sky.
Is coal renewable or nonrenewable?
Nonrenewable
What happens when light hits a mirror?
It reflects.
What happens to matter when an organism dies?
Decomposers break it down and recycle nutrients.
What does it mean to optimize a design?
Improve it to perform as effectively as possible within constraints.
At noon, shadows are shortest. What does this tell you about the Sun’s position?
The Sun is highest in the sky (more direct angle).
Why is freshwater considered a limited resource?
Only a small percentage of Earth’s water is usable freshwater.
Why can you see objects that are not light sources?
They reflect light into your eyes.
Why are decomposers essential in ecosystems?
They return nutrients to the soil.
Why might engineers test different materials for the same structure?
To compare strength, cost, and durability.
Why do we only see one side of the Moon from Earth?
The Moon rotates at the same rate it revolves around Earth.
How does overfishing affect ecosystems?
It disrupts food webs and reduces biodiversity.
Why do darker surfaces heat up faster than lighter surfaces?
They absorb more light energy.
How does carbon move from plants to animals?
Through consumption in food chains.
A bridge must hold 5 kg but use minimal material. What tradeoff must engineers consider?
Strength vs. material use (efficiency).
If Earth did not tilt on its axis, what would happen to seasons?
There would be little to no seasonal change.
Why is solar energy considered more sustainable than fossil fuels?
It is renewable and does not produce greenhouse gases during use.
If the angle of incoming light increases, what happens to the reflection angle?
It increases equally (angle of incidence = angle of reflection).
Why does matter cycle but energy does not?
Matter is reused; energy is lost as heat at each level.
Why is collecting quantitative data important during testing?
It allows objective comparison of solutions.
Explain why daylight hours are longer in summer than winter.
Earth’s tilt causes one hemisphere to receive sunlight for a longer portion of each rotation.
Explain how conserving forests helps regulate climate.
Answer: Trees absorb carbon dioxide and help stabilize ecosystems.
Explain why solar panels work best when directly facing the Sun.
Direct light transfers more energy than light at an angle.
Predict what happens if decomposers are removed from an ecosystem.
Waste and dead matter accumulate, and nutrients are not recycled.
After testing three prototypes, one is strongest but most expensive. Another is cheaper but slightly weaker. Explain how engineers decide which to choose.
They evaluate criteria and constraints (cost, performance, safety) to determine the best overall solution.