Thermal Energy and Temperature
Which describes temperature better: total kinetic energy of particles or average kinetic energy of particles?
Average kinetic energy of particles
Heat always moves from a warmer object to a ______ object.
Cooler
What type of heat transfer happens when particles pass energy by direct contact?
Conduction
Warm air rises and cool air sinks. What type of heat transfer is this?
Convection
What do we call a material that slows down heat transfer?
An insulator
A cup of water and a bucket of water are both at 50°C. Which one has more thermal energy?
The bucket of water
A metal tray and a cup of water both receive the same amount of heating. Which one will usually change temperature faster?
The metal tray
A metal spoon is left in hot soup. Why does the handle become hot after some time?
Heat moves through the spoon by conduction
You feel warmth from the Sun across space. What type of heat transfer is this?
Radiation
Why is air often useful in jackets, coolers, or some containers?
Because air is a poor conductor / a good insulator
What can you measure the temperature with?
thermometer
Why do coastal places often have smaller temperature changes than places far from the ocean?
Because water has a high specific heat and heats and cools slowly
Why is metal usually a better conductor than wood or plastic?
Because heat moves through metal more easily
In the hot-and-cold water food-coloring activity, the color spreads faster in hot water. What does this show about particle motion?
Particles in hot water move faster
A thermos keeps a drink hot for a long time. Is it designed to increase heat transfer or reduce heat transfer?
Reduce heat transfer
A student says, “If two objects have the same temperature, they must have the same thermal energy.” Why is this statement wrong?
Because objects with the same temperature can have different amounts of matter, so their total thermal energy can be different
Chloe lives close to equator. Which material should she use to make a front door with - wood or metal? why?
Wood, lower specific heat
Which material is the best at conducting heat - wool, fabric or metal? Why?
Metal, it has lower specific heat
During the day, land heats faster than the sea. The air above land rises, and cooler air moves in from the water. What process causes this moving air pattern?
Convection
In a class test, one group wraps a cup in wool and another wraps a cup in aluminum foil. Which material would you expect to work better as an insulator?
Wool
Give an example of something that does not have thermal energy
idea, creativity, emotions or any other appropriate answer
In an experiment, brick, iron, water, and oil are heated for the same time. Which material would you expect to change temperature the least?
water
A student touches a wooden desk and a metal desk in the same room. The metal feels colder. Does that prove the metal has a lower temperature? Explain in one idea.
No; metal feels colder because it transfers heat away from the hand faster
If you are in the sauna and feel that you want to have more heat, should you sit at the higher floor or lower? Why?
Higher, hot air goes up
A student says, “The best cooking pot should be made completely from insulating material.” Why is that a bad design?
Because the pot needs a conductor to transfer heat to the food