IS online_test_unit04b
--1--
Two birds of different weights are flying at the same speed. Which of the following statements is true?
A.The lighter bird has more kinetic energy.
B.The heavier bird has more kinetic energy.
C.The two birds have the same kinetic energy.
D.The two birds have zero kinetic energy.
--2--
A parachutist (跳傘者) is falling at an increasing speed. What is the change in kinetic energy and potential energy of the parachutist?
Kinetic energyPotential energy
A.increaseincrease
B.increasedecrease
C.remain unchangedincrease
D.decreasedecrease
--3--
A rollercoaster (過山車) is sliding down a slope. What is the energy change?
A.potential energy kinetic energy
B.kinetic energy potential energy
C.electrical energy kinetic energy
D.electrical energy potential energy
--4--
A basketball is thrown upwards and then falls back to the ground. What is the energy change of the basketball?
A.chemical energy potential energy sound energy
B.chemical energy kinetic energy + potential energy
C.kinetic energy potential energy sound energy
D.kinetic energy potential energy kinetic energy
--5--
A road washer (道路灑水車) is moving at a steady speed on a horizontal road while ejecting water to clean the road. What is the change in the kinetic energy of the road washer?
A.increase
B.remain unchanged
C.decrease
D.cannot be determined
--6--
Electrical energy is commonly used in our homes because
(1)it can be easily changed to other forms of energy.
(2)it can be carried through wires.
(3)it is clean to use.
A.(2) only
B.(1) and (2) only
C.(2) and (3) only
D.(1), (2) and (3)
--7--
Which of the following statements about kinetic energy is correct?
A.An object that moves faster must have more kinetic energy than another object that moves slower.
B.A heavier object must have more kinetic energy than a lighter object.
C.An object at rest has zero kinetic energy.
D.When two objects are moving at the same speed, the lighter one has more kinetic energy.
--8--
Bomb explosion is an uncontrolled energy conversion because
A.a large amount of sound energy is released.
B.a large amount of heat energy is released.
C.it is carried out in an uncontrolled way.
D.it occurs quickly.
--9--
When an energy converter changes energy from one form to another, only part of the input energy is changed to useful energy output. Some of the energy is wasted. Which of the following correctly shows the useful energy output and the wasted energy of the energy converter?
Energy converterUseful energy outputWasted energy
A.hair dryerkinetic energy, heat energysound energy
B.televisionlight energy, heat energysound energy
C.electric toothbrushsound energykinetic energy
D.light bulbheatenergylight energy
--10--
Which of the following are commonly used as fuels for cars in Hong Kong?
(1)LPG
(2)petrol
(3)diesel oil
A.(2) only
B.(1) and (2) only
C.(2) and (3) only
D.(1), (2) and (3)
--11--
Which of the following is NOT produced from crude oil?
A.LPG
B.coal
C.kerosene
D.petrol
--12--
When gas leak occurs in your home, what shouldn’t you do?
A.Close all windows to trap the gas inside your home.
B.Cut off the gas supply.
C.Call the police using phone outside your home.
D.Check if the gas cooker in your home is accidentally left on.
--13--
Which of the following statements about global warming and acid rain is true?
A.Both of them are caused by carbon dioxide produced in burning of fossil fuels.
B.Both of them lead to rise in sea level.
C.Global warming is caused by greenhouse gases while acid rain is caused by sulphur dioxide and nitrogen oxides.
D.There is no way to reduce global warming and acid rain.
--14--
Which of the following energy sources do not cause air pollution, but the amount of electricity generated is affected by weather condition?
(1)solar power
(2)wind power
(3)geothermal power
A.(1) and (2) only
B.(1) and (3) only
C.(2) and (3) only
D.(1), (2) and (3)
--15--
Solar-powered cars are more environmentally friendly than ordinary cars. However, solar-powered cars are not popular because
(1)they carry much less passenger.
(2)they are slower.
(3)they cannot run when there is not enough sunshine.
A.(1) and (2) only
B.(1) and (3) only
C.(2) and (3) only
D.(1), (2) and (3)
--16--
Which of the following are the advantages of using wind power?
(1)No fuel is needed.
(2)No waste or pollutant is produced.
(3)The output power is steady.
A.(1) and (2) only
B.(1) and (3) only
C.(2) and (3) only
D.(1), (2) and (3)
--17--
A tidal power station generates electricity from the difference in water level at low tide and high tide. Which of the following best describe the energy change involved?
A.sound energy potential energy electrical energy
B.potential energy heat energy electrical energy
C.potential energy kinetic energy electrical energy
D.heat energy kinetic energy electrical energy
--18--
Which of the following ways of generating electricity will cause the formation of acid rain?
(1)Burning fossil fuels
(2)nuclear power
(3)tidal power
A.(1) only
B.(1) and (2) only
C.(2) and (3) only
D.(1), (2) and (3)
--19--
Bungee jump is an exciting game. In bungee jump, a person jumps from a high place while connected to a large rubber cord. After falling through a distance, the person is slow down as the rubber cord stretches.
Which of the following best describe the energy change in bungee jump?
A.kinetic energy of the person potential energy of the person heat energy of rubber cord
B.kinetic energy of the person kinetic energy of rubber cord heat energy of rubber cord
C.potential energy of the person kinetic energy of rubber cord potential energy stored in rubber cord
D.potential energy of the person kinetic energy of the person potential energy stored in rubber cord
--20--
Which of the following ways can help save energy?
(1)Take a shower instead of a bath to reduce the use of hot water.
(2)Use electric fans instead of air-conditioners.
(3)Use compact fluorescent lamps.
A.(1) and (2) only
B.(1) and (3) only
C.(2) and (3) only
D.(1), (2) and (3)