Cup System
How does adding a lid help decrease the amount of water leaving the system?
The lid reduces exposure to air, slowing down evaporation.
Why do we need to agree on a list of procedures before conducting an investigation?
To make sure all steps are followed consistently by everyone
If we could completely seal off the cup, do you think the temperature of the liquid inside would still change? Why?
Yes, heat energy can still transfer to or from the cup’s surroundings.
How might we test the source of water droplets on the outside of a cup?
Add food coloring to the water inside and observe the droplets on the outside.
How can the structure of solid particles explain why water cannot leak through the walls of the cup?
Solid particles are tightly packed, preventing leakage.
Why might a cup with a lid keep liquids hot or cold better than a cup without a lid?
The lid reduces heat exchange between the liquid and the air.
If you tested 2 cups with the same amount of water and 1 has a lid while the other does not, what variable is being manipulated?
The presence of a lid.
How should heat interaction with a closed cup system be modeled?
A diagram showing heat energy moving into the cup and warming the liquid inside.
How does light energy affect the temperature of a liquid in a closed cup system?
Light energy can be absorbed and converted to heat energy, raising the temperature.
Imagine we could zoom in to a point where the liquid meets the wall of the cup. What do we think is happening to water molecules there?
The molecules bounce off the cup wall and stay in the liquid.
Based on the evidence from our experiments, does it support that heat is entering the cup or that cold is leaving the cup?
Heat is entering the cup.
How can we observe particles moving in plain water?
We can add food coloring to visualize the motion.
How does heat move? Does cold move too?
Heat moves from warmer areas to cooler areas; cold is the absence of heat.
In the context of light measurements, what is meant by transmitted light?
Light that passes through the material of the cup.
Why does putting on a lid cause the system to stop losing mass?
The lid traps evaporating water molecules inside.
What are two features that seem to matter the most for keeping a drink cold.
Insulation and material.
What role does particle movement have in understanding the temperature of a liquid?
Faster particle movement means higher temperature.
How does changing the temperature of the air outside the cup affect the water inside the cup?
The water inside will change temperature to match the air.
What can you conclude about the relationship between the amount of transmitted light and the water temperature in the cup?
More transmitted light increases the water temperature more.
What conclusion can be drawn about the effect of cup surface on water temperature if the foil-wrapped cup shows the smallest temperature change?
Reflective surfaces like foil prevent light absorption and thereby reduce temperature increase.
How does increasing the number of particles affect the total kinetic energy of a gas?
The total kinetic energy increases.
Why do particles move more in hot liquids?
They have more kinetic energy.
If the iced drink warms up, what happens to the temperature of the air right outside the cup?
The air right outside the cup cools down slightly.
What was one of the key conclusions from Joule’s experiment?
Movement of liquids causes temperature changes.
If we zoomed into the particles of hot tea, what would we observe compared to iced tea?
Particles in hot tea move faster than those in iced tea.