Test items and tasks – Energy



Objective items

1. What is the source of energy in the following situations?

a. a girl pedals her bicycle along the street

b. a drag racing car spins its tyres and hurtles down the track

c. a eucalyptus tree grows to a height of 80 m.

2. Each of the machines listed below wastes some energy when it operates. Complete the table by listing the desired forms of energy and the waste forms of energy produced by each machine.

|Machine |Desired forms of energy |Types of waste energy |

|Electric light globe | | |

|Electric food mixer | | |

|Car engine | | |

3. Indicate which of the following energy sources are renewable (R) OR

non-renewable (N).

|Energy source |R or N |

|Coal | |

|Solar | |

|Wind | |

|Wood | |

|Uranium | |

|Natural gas | |

4. What are the main advantages and disadvantages of the following sources of energy?

|Source of energy |Advantage |Disadvantage |

|Gas | | |

|Nuclear | | |

|Wind | | |

5. A model rocket with a fuel motor is launched from the ground. It flies to a height of

100 m and then falls back to the ground.

a. Complete the table to show the types of energy present at each stage of the flight.

|Stage of flight |Types of energy present |

|The rocket is sitting on the launch pad. | |

|The rocket has been fired and is now 20 m off the ground. | |

Table continued p 2

|The fuel is used up, the motor has cut out and the rocket has reached| |

|its maximum height, it is still and about to fall back towards the | |

|ground. | |

|The rocket is falling back towards the ground. | |

|The rocket is back on the ground. | |

b. At which stage did the rocket have the greatest total energy?

c. At which stage did the rocket have least total energy?

1. Consider the experimental results in the tables below and the way you would plot graphs of the results.

a. Electricity generated by a wind turbine.

|Wind speed (km/h) |Electricity generated kW/h |

|10 | 85 |

|20 |163 |

|30 |232 |

|40 |325 |

What type of graph would you use?

Which variable would you plot on the horizontal axis of the graph?

b. Electricity generated by a bank of solar cells under different cloud conditions.

|Electricity generated kW/h |Cloud cover |

| 5 |Complete cloud cover |

|23 |Many clouds |

|65 |Few clouds |

|122 |Clear sky |

What type of graph would you use?

Which variable would you plot on the horizontal axis of the graph?

2. One advantage of solar energy is that it:

a. is not renewable

b. is efficient in any climate

c. is available at all times

d. is non-polluting.

Extended response items

For items 9 and 12, use separate sheets of paper.

3. For her definition of energy, Helen wrote ‘Energy is a substance that can move or change the movement of something’. Comment on Helen’s definition. How would you improve it?

4. Write a short newspaper story (about 2/3 of a page) about the day when the world runs out of fossil fuels (about 175 years in the future). In your story explain the history of energy use by humans and how future generations will meet their energy needs. Make sure you include a headline for your story.

5. As fossil-fuel energy sources get used up, which energy sources do you think would make the best substitutes for them?

6. It is expected that the cost of electricity will increase considerably over the next 10 years. How could typical Australian families make the greatest savings in electricity consumption in their homes?

7. Draw an energy chain diagram to show how the potential energy of water in a dam is converted into electricity in a hydroelectric power plant. Include in your diagram any forms of waste energy produced by the power plant.

8. What changes will we have to make to our uses of energy if air pollution and the greenhouse effect are to be reduced?

9. Electrical energy is used to power a lamp. The amount of light energy produced is:

a. more than the amount of electrical energy used

b. the same as the amount of electrical energy used

c. less than the amount of electrical energy used.

Give a reason to support your answer:

Activity-based items

Elastic band energy

Materials required: 3 different elastic bands, 35 cm ruler and a spring balance

Procedure

1. Take one of the elastic bands, hook it over the end of your ruler and use the spring balance to pull the band until it is stretched to the 12 cm mark of your ruler. Record the reading on the spring balance.

2. Repeat for each elastic band and make sufficient measurements so that you can compare the three elastic bands.

3. Record all of your measurements.

Questions

a. Which band required the greatest force to stretch it to 12 cm? How confident are you of this? Explain.

b. What type of energy does the band have when it is stretched?

c. If you were to plot a graph of your results, what type of graph would you draw? Which variable would you plot on the horizontal axis of the graph?

d. How could you have improved your investigation?

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download