Engineering a Better Design

What is the process called when energy transfers from one particle to another when particles collide?

• Radiation

• Conduction

• Convection

• Reflection

A thermos keeps hot liquids hot and cold liquids cold by:

• reducing heat transfer between the inside and outside

• adding heat to hot liquids and removing heat from cold liquids

• using ice packs for cold liquids and heaters for hot liquids

• changing the temperature of the liquid automatically

Explain how scientists learn about the properties of insulation.

• Scientists learn about properties of insulation by developing theories and conducting tests. Their evidence and reasoning lead to models that explain why certain materials are good insulators.

• Scientists only guess which materials are good insulators without any testing.

• Scientists rely solely on historical beliefs about insulation properties.

• Scientists choose insulators based on their color and appearance.

Strategic Thinking: Scientists and engineers often work together to solve engineering problems. How might they use their knowledge of insulation to solve a real-life problem?

• By designing buildings that retain heat in winter and stay cool in summer

• By creating new types of engines for cars

• By inventing new communication devices

• By developing faster computers

What is the purpose of the vacuum layer in a thermos?

• To keep the thermos shiny

• To prevent energy transfer by conduction

• To make the thermos heavier

• To allow air to circulate inside

Fill in the blank: The space between the two layers of a thermos is called a _________?

• vacuum

• insulator

• membrane

• filter

A vacuum is the best insulator in a thermos because:

• It prevents heat transfer by conduction and convection.

• It allows heat to escape quickly.

• It increases the temperature inside the thermos.

• It absorbs heat from the surroundings.

According to the passage, what does the vacuum layer in a thermos do?

• It slows the overall rate of conduction.

• It increases the temperature inside the thermos.

• It allows heat to escape quickly.

• It absorbs all the heat from the contents.

According to the passage, what are some criteria that engineers consider when designing insulation for a building?

• How large the building will be

• the climate

• fire safety

What are some constraints engineers must consider when choosing insulation materials?

• Cost of materials and work

• Health concerns related to materials

• Construction deadlines