Give one example to show that heat is a form of energy
What is temperature? Name the scales used to measure it.
3. If the hotness or coldness of a body is relative, how do we measure its degree of the
7. Mention three changes that heat causes in substances.
5. A steel spoon dipped in a pot of boiling soup for a few minutes becomes too hot to touch. Here
does heat travel through the spoon?
because test
6. How is it that we can hold a match while it is burning?
How does turning on a heater in a room make the whole room warm?
18. How does heat from the sun reach the earth?
9. Mention one similarity between heat and light.
10. When two bodies are in contact, heat flows from the hotter to the colder body. When does heat
he earth? A3
stop flowing?
Answer the following in not more than 40 words.
1. Distinguish between the Celsius and Fahrenheit scales.
2. When a pan of water is heated on a gas stove, all the water turns hot in a while. How does heat
travel through the water? ooplon ako
by a body depend on?
me difference between the transfer of heat by conduction and that by radiation.
rence between the transfer of heat by conduction and that by convectic
vords.
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1. What happens to radiant heat when it falls on a body? What does the absorption of radiant heal
Answers
Answer:
Explanation:
thermometer is a glass tube filled with a liquid (mercury) which expands or contracts depending on the temperature of the object it is in contact with. It measures the average kinetic energy (one type of thermal energy) of the molecules of a substance in degrees Fahrenheit (F) or Celsius
Answer:
1. Heat is a form of energy which produces a sensation in our body by way of which we make out whether a body is cold,warm or hot..
⇒To showthat heat is a form of energy, rub your both hands together. It will generate heat energy.
2. Temperature is how or cold an object is.
⇒There are three temperature scales in use today, Fahrenheit, Celsius and Kelvin.
3. We can measure the degree of temperature by a thermometer.
4. Heat can change the following in substances:
→Heat can change the temperature of a substance.
→Heat can expand a substance.
→Heat can change the state of a substance.
5. Heat travels through the spoon in the process of conduction.In the process of conduction heat is transferred through solid, steel spoon is solid and also a good conductor of heat.
6. Matches are made up of wood and wood is a bad conductor of heat, so it will not transfer heat.
Room heaters are placed on the floor of a room. When the cool air is heated, it rises up and the cold air flows down to the floor. This results in effective heating of the entire room.
7. Radiation.
8. Both heat and light forms of energy.
9. Heat will stop flowing when both the objects/substances have the same temperature.
_____________
1. Celsius scale, or centigrade scale, is a temperature scale that is based on the freezing point of water at 0°C and the boiling point of water at 100°C. Fahrenheit scale is a temperature scale that is based on the freezing point of water at 32°F and the boiling point of water at 212°F.
2. When water is heated, hot water rises up. Cold water from the sides rushes to take it's place and it rises up too. This process is continued till the entire water is heated and is called convection.
Conduction and radiation difference:-
Conduction is the transfer of heat in which two objects are in contact with each other. It takes place in solids. Heat transfer is slow in conduction.
Radiation is the transfer of heat through electromagnetic waves. It takes place without any medium. Heat transfer is fast in radiation.
Conduction and convection difference:-
Conduction takes place in solids. The heat transfer in conduction takes place due to the difference in temperature.
Convection takes place in fluids (liquids and gases). The heat transfer in convection occurs due to the difference in density.
3. When the radiant heat falls on a body, part of it is absorbed and the rest of it is reflected back. The absorption of radiant heat by a body depends on its absorptive, reflective and transitive properties.