heat Flashcards
heat?
the total kinetic energy of molecules that can flow from hotter to colder bodies. Its si unit is joule (J)
temperature?
the degree of hotness or coldness
transmission of heat?
the process of the flow of heat form a hot to a cold body
conduction?
the process of transmission of heat from one point to another in a body without actual movement of molecules.
convection?
The process of transferring heat energy from one place to another by the actual movement of heated molecules.
radiation?
the process of transmission of heat without any material medium.
how is land breeze formed?
At night, the land cools faster than the sea which causes the air over the sea to rise and create a low-pressure area. the cool air over the land flows into the low-pressure area of the sea. The warm air rises and cool air sinks which forms a land breeze.
how is sea breeze formed?
During the day, land heats faster than the sea which causes the air over the land to rise and create a low-pressure area. the cool air over the sea flows into the low-pressure area of land to replace the rising warm air. the warm rises and cool air sinks which forms sea breeze.
the uses of conduction
- essential for cooking as it ensures that heat is evenly distributed to cook food thoroughly.
- used to make the handles of kettles, pans, etc.
- used in heating and cooling systems in homes and buildings.
- used to keep us warm in cold weather.
- used for ironing clothes.
- important in preventing electronic devices from being overheated.
convection current?
the movements created by the uneven heating of fluid which creates the current.
conductor and insulators?
the substances which allow heat to conduct through them.
the substances that do not allow the heat to conduct through them.
how do convection currents affect weather patterns of the planet?
plays an important role in weather and climate patterns. it is one of the primary mechanisms by which heat is transported in the atmosphere. can contribute to the formation of weather patterns such as thunderstorms, hurricanes, and tornadoes. occurs when warm air rises and cool air sinks, creating currents that can lead to the development of clouds, thunderstorms, and other forms of precipitation.
thermos flask?
a container that is used to keep hot liquids hot and cold liquids cold for an extended period of time.
examples of uses of radiation
- a microwave uses radiation to cook food by passing microwave energy through the food.
- solar panels convert sunlight to heat for use in homes and buildings
- radiation therapy is used to treat cancer.
- UV radiation is used in water treatment systems to kill bacteria and viruses.
- satellites are used to predict weather patterns and monitor environmental changes.
why should ventilators be kept in our rooms?
to circulate air and regulate indoor temperature without using mechanical systems.
why is a vacuum made between the walls of the thermos flask?
to reduce the flow of heat by conduction to convection to a great extent as material medium required for the transmission of heat by conduction or convection.
why is an iron rod a good conductor of heat?
as iron has high thermal heat conductivity that can quickly transfer heat.
how does convection current play a sufficient role in the earth’s climate?
as convection current helps to regulate the temperature of the earth and weather patterns by distributing heat and moisture around the earth as the molecules circulate freely from warmer to colder regions by convection.
The cups of tea and coffee are made of Porcellian.
Porcellian has low thermal conductivity, which reduces heat transfer and helps to warm tea or coffee for longer.
Wearing white or light colored clothes are common in the summer.
Because white or light-colored clothes are good reflectors of heat and have high thermal conductivity, which can draw heat away from the body.
ventilators are set just above the door and near the ceilings.
to remove hot air and circular cool air throughout the room as warmed fluid is less dense and rises up and cool fluid is dense and sinks to the bottom and replaces warm fluid due to convection current.
the internal environment of the house made up of mud and rocks is cool in summer.
bc mud and rocks are insulators that have low thermal conductivity that prevents or traps heat inside the house in winter and doesn’t allow heat to enter in the summer.
Uses of convection
- used to distribute heat from the electronic parts in the devices like computers and smartphones
- used for heating, cooling, boiling, distillation, and drying in various industries
- convection oven use a fan to circulate hot air which cooks food faster and more evenly than a traditional oven
- AC systems and fans use convection process to remove hot air and circulate cool air throughout a room
