Objective 01: Heat Calculation on Solids, Liquids, and Vapours

Question 1

What are some of the many forms of Energy?

Answer 1

1. Mechanical
2. Electrical
3. Thermal
4. Chemical
5. Nuclear

Question 2

What are some important uses of Energy?

Answer 2

1. Doing Work directly
2. Keeping things warm or cool
3. Powering machinery
4. Carrying information

Question 3

Energy

Answer 3

The capacity to do work, measured in Joules

Question 4

What are 2 general forms of Energy?

Answer 4

1. Kinetic Energy, due to motion

2. Potential Energy, due to position or state

Question 5

How does a Plant generally transform chemical energy in fuel to electrical energy?

Answer 5

1. Fuel enters the boiler furnace where it is burned, thereby releasing large quantities of thermal energy which appears as heat
2. This heat energy is then transferred from the boiler furnace into water to produce steam
3. The high-pressure steam contains thermal energy due to its high temperature and potential energy due to its high pressure
4. When directed through the blades of a turbine, the temperature and pressure of the steam drop as the steam uses energy to do work on the blades
5. This work appears as rotary mechanical energy as it drives the generator to produce electricity

Question 6

Power

Answer 6

The rate at which work is done or energy is used, measured in Watts

Question 7

Is 1 kilowatt larger than 1 horsepower?

Answer 7

Yes

Question 8

How is electrical energy usage/production measured?

Answer 8

By estimating the amount of power used over a period of time, measured in kWh.

Question 9

Heat Movement

Answer 9

Energy moving from one body to another due to a temperature difference between the two bodies, measured in Joules

Question 10

In what direction does heat travel?

Answer 10

From a body of higher temperature to a body of lower temperature.

Question 11

What does the quantity of heat contained by a body depend on?

Answer 11

1. Mass
2. Temperature
3. Specific Heat

Question 12

What is the freezing point of water at atmospheric pressure in Fahrenheit?

Answer 12

32ºF

Question 13

What is the boiling point of water at atmospheric pressure in Fahrenheit?

Answer 13

212ºF

Question 14

What is an equivalent measure of the Fahrenheit scale?

Answer 14

Rankine

Question 15

How does Rankine differ from Fahrenheit?

Answer 15

Rankine starts at absolute zero (-460ºF)

Question 16

What is an equivalent measure of the Celsius scale?

Answer 16

Kelvin

Question 17

How does Kelvin differ from Celsius?

Answer 17

Kelvin starts at absolute zero (-273.15ºC)

Question 18

What does 1 Joule equal in terms of work?

Answer 18

The work done by a force of one newton moving through a distance of one metre in the direction in which the force is applied

Question 19

Specific Heat

Answer 19

The quantity of heat required to raise the temperature of a unit mass of the substance by one degree

Question 20

What is the difference in measuring Specific Heat between the SI system and the Imperial system?

Answer 20

SI system measures in kJ/kgºC whereas the Imperial system measures in Btus/lbºF

Question 21

Sensible Heat

Answer 21

Heat transferred within a thermodynamic system that changes the temperature of the system without effecting a change of state

Question 22

Latent Heat

Answer 22

Energy absorbed or released by a thermodynamic system during a constant temperature process affecting a change of state

Question 23

What are 3 factors that affect the quantity of heat absorbed by a substance when it is increasing in temperature?

Answer 23

1. Temperature rise
2. Mass of the substance
3. Specific heat of the substance

Question 24

Specific Heat Capacity

Answer 24

The ability of a material to store energy per unit mass

Question 25

Describe the Specific Heat Capacity of mixtures

Answer 25

They have both individual heat capacities from each component but also a collective heat capacity for the mixture as a whole