Heat and Materials Flashcards
What is a conductor?
A material that allows heat to pass through it easily.
Why does a metal spoon feel hotter than a wooden spoon when placed in hot water?
Because metal is a better conductor of heat than wood.
What is an insulator?
A material that does not conduct heat well, like wood or plastic.
Why do we use glass or metal dishes in an oven instead of plastic?
Plastic melts easily, but glass and metal can withstand high temperatures.
Which has a higher specific heat: water or sand?
Water has a higher specific heat than sand.
True or False: Sand heats up faster than water because it has a lower specific heat.
True
True or False: Insulators help transfer heat quickly.
False (Insulators slow the transfer of heat.)
True or False: Thermal expansion causes materials to contract as they heat up.
False (Materials expand when heated.)
True or False: Metal is a good conductor because it allows heat to transfer easily.
True
True or False: Wool and air are examples of insulators.
True or False: Wool and air are examples of insulators.
Why does water take longer to heat up than sand?
It has a higher specific heat capacity
What happens to the particles in a material as it cools down?
They move closer together
Which material would be the best insulator?
Wool
What causes popcorn to pop?
Heat from the microwave expanding water vapor inside the kernel
How does thermal expansion help you open a stuck jar lid?
When you run hot water over the lid, it expands more than the glass jar, loosening the lid.
What is the formula to calculate energy change when a material’s temperature changes?
Energy Change = Mass × Specific Heat × Temperature Change
Describe why metal feels cold to touch even at room temperature.
Metal is a good conductor and transfers heat away from your hand quickly, making it feel cold.
Explain how popcorn pops using thermal expansion and kinetic energy.
Heat causes the water inside the popcorn kernel to turn to vapor. As the vapor expands, it builds pressure until the kernel pops. This expansion is related to the increase in kinetic energy as the temperature rises.
If you heat 2 kg of water and its temperature rises by 5°C, and the specific heat of water is 4,186 J/kg*K, how much energy was used to heat the water?
41,860 J
Why do cracks often appear in concrete sidewalks or roads during very hot weather, and how is this related to thermal expansion?
Cracks appear in concrete sidewalks or roads during very hot weather because concrete expands as it heats up. When the temperature rises, the particles in the concrete spread out and cause the material to expand. If there isn’t enough space for this expansion, the concrete can crack. This is a result of thermal expansion, which happens when materials increase in volume as their temperature increases.
