Chapter 5. Heat. A. Answer in brief. 1. In which direction does the transfer of heat Normally take place? 2. What is the cause of heat generation in following situation - a. We apply brakes on our fast moving car. b. People often jump up and down to feel warmer in cold weather . 3. State two types of physical change that may take place when a substance is heated? 4. In what ways does clinical thermometer differ from ordinary thermometer? 5. State the mode/diffrence modes of heat transfer in following situations- a. A paper cup full of hot soup lying on a table. b. Cooking vegetable in a pan. c. Melting of a chocolate bar in school bag on a hot day. d. Cooking food in a microwave oven. 6. What is meant by breeze ? when does it occur? Tell me all answer correctly please.
Answers
Explanation:
Chapter 5. Heat. A. Answer in brief. 1. In which direction does the transfer of heat Normally take place? 2. What is the cause of heat generation in following situation - a. We apply brakes on our fast moving car. b. People often jump up and down to feel warmer in cold weather . 3. State two types of physical change that may take place when a substance is heated? 4. In what ways does clinical thermometer differ from ordinary thermometer? 5. State the mode/diffrence modes of heat transfer in following situations- a. A paper cup full of hot soup lying on a table. b. Cooking vegetable in a pan. c. Melting of a chocolate bar in school bag on a hot day. d. Cooking food in a microwave oven. 6. What is meant by breeze ? when does it occur? Tell me all answer correctly please.
Answer:
1. Heat normally travels from a hotter to cooler region.
2a. The friction from the brake causes heat.
2b. To allow heat in blood to be transported all over the body.
3. Melting and Evaporation
4. Clinical thermometer is digital and provides faster results and is more often accurate than normal thermometers.
5a. Radiation
5b. Heat conduction
5c. Heat conduction
5d. Heat convection
I do not understand question 6. Does the 'breeze' refer to gentle winds?
Explanation:
2a. The brakes in the car will stop the motion creating friction which produces heat
2b. Few people know this but blood actually transfer heat around the body as well as digested food and oxygen etc. People jump around to increase heart rate and blood flow to ensure that enough body heat is available. An example of body instinct to regulate body heat is shivering.
4. Normal thermometers are referred to those with mercury. More often, mercury takes a longer time than the heat sensor in the clinical thermometer to measure the temperature and is less reliable.
5. As you should know, the 3 types of heat transfer;
heat conduction: heat pass through solid
heat convection: heat pass through liquid/gas
heat induction: heat pass through electromagnetic waves