Cups
What is the main purpose of using an insulated cup for beverages?
To maintain the beverage’s temperature
What is the smallest particle of water called?
A molecule
What process describes the transformation of liquid water into gas?
Evaporation
Which of the following is a characteristic of a closed system?
No matter can enter or exit
A student puts a cold drink in a cup and notices water droplets forming on the outside of the cup. What is the best explanation?
A. Water from inside the cup leaked through the cup.
B. Water vapor in the surrounding air cooled and changed into liquid water.
C. The cup created new water when it became cold.
D. The cold drink caused the cup to produce water.
B. Water vapor in the surrounding air cooled and changed into liquid water
Which of the following best describes why a cup with a lid keeps a drink’s temperature better than a cup without a lid?
It reduces the rate of heat transfer to the environment
Which statement is true about the particles in a gas?
They have a lot of space between them
Where do the water droplets outside a cold cup come from?
The air outside the cup
What aspect would be considered when developing a thermal cup in developing possible solutions?
The type of insulating materials to use
Two cups contain the same amount of water. Cup A is at 20°C and Cup B is at 60°C. Which statement best describes the particles in the water?
A. The particles in Cup A are larger than those in Cup B.
B. The particles in Cup B are moving faster on average than those in Cup A.
C. The particles in Cup A are not moving.
D. The particles in Cup B have changed into a different substance
B. The particles in Cup B are moving faster on average than those in Cup A
How does adding more walls or layers to a cup affect its insulation properties?
Increases insulation by trapping air, which reduces heat transfer
Why does a solid not change shape like a liquid or gas?
Its particles cannot move freely
Why does the evaporation of a liquid from the surface lead to cooling?
It removes heat energy from the liquid, lowering its temperature
What role does electromagnetic radiation play in the context of thermal cups?
Heat can travel as invisible radiation, and shiny surfaces inside some thermal cups help reflect that heat back in
A student places two identical cups of water under a light. One cup is covered with a shiny material, while the other is not. The uncovered cup gets warmer.
Which explanation BEST describes why?
A. The uncovered cup absorbed more light energy.
B. The shiny cup created cold energy.
C. The uncovered cup gained more water from the air.
D. The shiny cup caused the water particles to stop moving
A. The uncovered cup absorbed more light energy
Why is using a lid on a thermal cup an effective strategy to keep drinks at the desired temperature?
It creates a barrier to heat transfer by convection and evaporation
How do liquids differ from gases?
Liquid particles are closer together than gas particles
What phenomenon explains the condensation of water on the outside of a cold cup?
The cold surface cools the air around it, causing water vapor to condense into liquid
What is key in defining an engineering problem when designing a thermal cup?
Determining how to minimize thermal energy transfer
You are designing a cup that needs to keep a hot drink hot for as long as possible. Which design would BEST reduce thermal energy transfer?
A. A single thin metal wall with no lid
B. Multiple layers with trapped air and a lid
C. A cup with holes throughout the sides
D. A cup made from a material that allows energy to move through it quickly
B. Multiple layers with trapped air and a lid
Why are cups with more layers more effective at insulation (reducing thermal energy transfer?
They have more barriers to heat transfer, trapping air that acts as an insulator
What happens to particles in a liquid when it turns into a gas?
They move apart and move freely
What does the mass of a closed system tell us about matter transfer?
Matter does not enter or leave, so the mass stays constant
How do particles in a solid compare to those in a liquid regarding movement?
Particles in a solid vibrate in place, while those in a liquid move around freely
A student measures the temperature of water in a closed cup every five minutes while a light shines on it. The temperature increases from 20°C to 28°C, but the mass of the cup system stays the same.
What is the BEST conclusion?
A. New matter entered the system and made the water warmer.
B. Some of the water disappeared as energy entered the system.
C. Energy was transferred into the system, increasing the average kinetic energy of the particles.
D. The particles became larger because the temperature increased.
C. Energy was transferred into the system, increasing the average kinetic energy of the particles.