Thermal Energy
What is the function of a thermos?
(Answer: Minimize thermal energy transfer)
Which of these is potential energy: sound, motion, electrical, or chemical?
(Answer: Chemical)
Why is the city usually warmer than rural areas?
(Answer: Asphalt absorbs more thermal energy; grass cools the air)
What is one constraint engineers faced when designing a sous-vide machine?
(Answer: Must be under 18 inches each side, inexpensive, etc.)
Which bag (black or white) would heat water better for Kevin’s shower?
(Answer: Black bag)
Which bathtub has more thermal energy if both are at the same temperature but one holds more water?
(Answer: The larger bathtub)
A swimmer does a cannonball into the pool. What happens to the swimmer’s energy?
(Answer: Kinetic energy of swimmer is transferred to water)
Which material makes the best cooling sheet for granola bars: copper, bronze, iron, or tungsten?
(Answer: Copper)
Why does oil cook food differently than water?
(Answer: Different thermal conductivity)
What is the source of thermal energy that heats the food in the sous-vide?
(Answer: From the container → to food)
What is the measure of the average kinetic energy of particles?
(Answer: Temperature)
What happens to an object’s thermal energy if more of the same type of mass at the same temperature is added?
(Answer: Increases)
What happens to temperature if more mass at the same temperature is added?
(Answer: Stays the same)
In the aquarium heater, where does transformation of energy occur?
(Answer: Electrical → Thermal in the rod)
Why do attics get hotter than the rest of the house?
(Answer: Radiation from sun + convection inside)
What type of energy transfer involves no particles?
(Answer: Radiation)
In the wind-up music box, what type of energy is transferred through the crank and transformed by the pins?
(Answer: Kinetic → Sound)
In Kim’s attic, which process explains warm air rising?
(Answer: Convection)
Describe one way the sous-vide engineer could improve the design for even heating.
(Answer: Better circulation, stronger heater, different material)
What happens when you use a metal vs wooden spoon in hot soup?
(Answer: Metal transfers heat faster → conduction)
In Kevin’s shower problem, how is thermal energy from the sun transferred to heat water?
(Answer: Radiation heats the water, conduction transfers heat through the bag, convection circulates warm water)
What kind of energy is stored when a diver stands on a diving board?
(Answer: Potential energy)
What kind of transfer happens when you touch a hot pan?
(Answer: Conduction)
Give one criterion in Kevin’s shower problem that involves energy transfer.
(Answer: Needs to absorb heat from the sun efficiently)
In the sous-vide trials, why didn’t the potato heat evenly?
(Answer: Thermal energy did not fully transfer to the core, needs better heat distribution)