Answer the following in not more than 20 words.
1. Give one example to show that heat is a form of energy
2)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 hotness?
4. 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. How does heat travel through the spoon?
6. How is it that we can hold a match while it is burning?
7. How does turning on a heater in a room make the whole room warm?
8. 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
stop flowing?
Answers
Answer:
1.Here are some common examples of heat energy. The biggest example of heat energy in our solar system is the sun itself. The sun radiates heat to warm us up on the planet earth. When the burner of a stovetop is very hot, it is a source of heat energy.
2.Temperature is a physical quantity that expresses the hotness and coldness of the object. Temperature Scales. There are three temperature scales in use today, Fahrenheit, Celsius and Kelvin.
3.Make sure the relative importance, of the measuring device’s, are maximal relative to their containers. For example a temperature probe may have a shield around it which takes a long time to get warmer or hotter and the sensor might be in only part of the shield and parts of the shield might be in places with different temperatures — like a Mercury of Alcohol thermometer where the glass tube as to be all in the place of measurement and for long enough for the insides to equal the glass so time has to pass for the differences to be equal between the insides of the thermometer and the whole length.
4.a)Expansion: When heat is added to any substance, the particles gain energy and vibrates(with more speed) or vigorously about their fixed positions, forcing each other further apart. ...
b)Increase in temperature: When heated there is increase in kinetic energy and particles move at higher speed. ...
c)Change in state.
5.heat travel through the spoon in the process of conduction in the process of conduction heat is transferred through solid so spoon is solid and good conductor of heat.
6.Matches use sulfur, phosphate and a friction agent held together by a binding agent. With a match, heat ignites the phosphorous on the head of the match. To keep the fire going, the match needs more oxygen than is available from the air alone.
7.room heating by a convection heater. CONVECTION: room heating by a convection heater: heat is distributed in a fluid by convection. As the fluid near the heat source warms up it expands, gets less dense, and rises.
8.Most of the electromagnetic radiation that comes to the earth from the sun is invisible. ... Most of the solar radiation is absorbed by the atmosphere and much of what reaches the earth's surface is radiated back into the atmosphere to become heat energy.
9.Although light and heat are two different entities, there are a few similarities between them. As we all know, light and heat, both are the forms of energy and this energy is acquired from the sun, which is the ultimate source of energy. One more similarity is, both light and heat have wavelength and frequency.
10.When you bring two objects of different temperaturetogether, energy will always be transferred from the hotter to the cooler object. The objects will exchange thermal energy, until thermal equilibrium is reached, i.e. until their temperatures are equal. We say that heat flows from the hotter to the cooler object.