MIND MAP:VIBRATION AND WAVE

PHYSICS: WAVE

What is wave?

Waves is the vibration that travels through an object from one place to another or a wave can be described as a disturbance that travels through a medium from one location to another location.

There are 2 types of waves: 

1. Transverse Waves

Transverse waves happen on a rope or on water. Transverse waves are always in a form of a peak and a valley of the wave. The height of the peak and the valley is considered as the amplitude of the wave. A complete wave is always consists of one peak and one valley of the wave. A complete wave is called a wave-length.

An example of transverse waves. There is always a peak and a valley for each complete wave.

2. Longitudinal Waves 

Longitudinal waves are waves that have a compression part and a expansion part, instead of a peak or valley. A complete wave of a longitudinal wave consists of one compression part and one expansion part. The length of a longitudinal wave is equal to the length of a wave that consists of a compression part and a expansion part.

An example of longitudinal waves. You can see a compression and a expansion every wave.

Examples:

1 complete wave = a - b - c - d - e
It consists one peak (a) and one valley (c)

A to B = 1/4
A to C = 1/2
A to D = 3/4

A to E =  1 wave 
A to H =  1 3/4 wave
A to G = 1 1/2 wave 
B to C = 1/4 wave
B to E = 3/4 wave

Exercise On Chapter 18 

1.   Look at the following figure of a pendulum. A motion of 2 Vibrations is shown as the following successive motion .......

   answer:  (B): 2-3-2-1-2-3-2-1












2. Look at the following figure of a pendulum. The part which is considered as the amplitude is . . . .

 answer:  A AND B 

3.    Look at the following figure of a spring. if the spring moves as a-b-c-b-a-b-c-b-a, its motion performs.......

answer: 2 FULL VIBRATION

4.   The number of vibrations performed in every second is ........

                                                   answer: THE FREQUENCY

5.   If a vibration happened in 30 second, the correct statement in the following information is......

                                                      answers: ITS PERIOD IS 1/4 SECOND


6.  A period of a swing is 20 seconds. in every minute, the pendulum will perform......

                                                      answer: 3 SWINGS
              

7.  look at the figure of ruler that is placed on a table. If in 1/4 seconds the ruler moves in the b-c-b-a-b-c-b pattern, period of the vibration made by the ruler is .......


answer:  t/n = (1/4)/(1 1/2)
                  = (1/4)/(3/2)
                  = 1/4 x 2/3
                  = 2/12 = 1/6 seconds





8. If the frequency of a vibration is 340 Hz, the period of such a vibration is........

                                                   answer: (B): 1/340



9.  A pendulum performs swings with a frequency 10 Hz. the number of vibrations that it can make within 5 minutes is.........

                                                     answer:   

                                                             10 Hz => 10 vibrations in one second
                                                             => ? vibrations in 300 seconds (5 min)
                                                              ? = 10 x 300
                                                                 = 3000



Vibration is not just about the back and forth motion an object is doing, but vibration also includes:


- Frequency


-Period


-Amplitude





Frequency = Number of vibration in one second


                             formula:    F=N/T


 Period = Time needed for one full vibration


                            formula:     P=T/N


Amplitude = The distance between the maximum distance and the stable motion




                           

                          T = 1/F  second  OR    F = 1/F Hz




                                

                           SI unit for frequency = Hz (Hertz)

                 

                               SI unit for period = s (seconds)




Example:





Frequency:    


 1. What is the frequency of......


a) 2 second -> 4 vibration?

Answer = 4 ÷ 2 = 2 Hz

b) 5 seconds -> 35 vibration?

Answer = 35 ÷ 5 = 7 Hz      






2. What is the period of.......




a) 2 vibration -> 18 seconds?

Answer = 18 ÷ 2 = 9 seconds


b) 5 vibration -> 125 seconds?

Answer = 125 ÷ 5 = 25 seconds

 

 

VIBRATION

      WHAT IS VIBRATION?

A vibration is the motion of the object that are moving back and forth of an object passing through a balance position . The oscillating motion is called a Vibration

EXAMPLES OF VIBRATION MOTION:
these are the common examples of vibration such as the following:


                                                 1.     Vibration of a pendulum

A swinging Pendulum

                  
                                                     2.    Vibration of a plastic ruler

a plastic ruler making a vibration

3.    Vibration of a spring

a spring makes vibration

            CALCULATION OF VIBRATION / HOW TO KNOW THE MOTION OF VIBRATION

a swinging pendulum

Vibration is calculated by how many times the object moves back and forth. For Example:

 The motion is : 1 - 2 -3 - 2 - 1

*A motion of one vibration is always 4 counts, and we do not count the first one as it is the original position of the object and where the vibration starts from.*


OTHER EXAMPLE OF VIBRATION MOTIONS:

a vibration of...........

1/2:       1 - 2 - 3

1/4:       1 - 2

3/4:      1 - 2 - 3 - 2

SELF ASSESSMENT 15.6

 1. FOSSIL FUEL ARE CONSIDERED AS A SOURCE OF ENERGY WHICH IS NOT RENEWABLE. WHY IS IT SO?

Fossil fuels are considered non-renewable sources of energy because when they are burnt, they are finished. When the last barrel of oil has been pumped out of the ground there is no more. And also it's non-renewable because fossil fuels take hundreds of millions of years to form under the Earth's surface. It will take another million years for more to be produced, so we only have a limited supply. 

2. WHAT HAPPENS IF THE FUEL CONSUMPTION IS NOT SPREAD?

If fuel consumption is not spread, its going to be harder for us to live. Since fossil fuels are used to power thing up for example oil is use for cars, coal for industries, natural gas for stove, and many others. So thats why if fuel consumption is not spread is going to be harder for us to live. And because of that we have to use alternative energy like solar and wind energy.

3. WRITE DOWN THE DANGEROUS ISSUES OF HAVING A NUCLEAR POWER PLANT.

Although nuclear power plants offer an new source of energy, nuclear power plants could also be dangerous as it is radioactive. For example in Japan when there was tsunami. The tsunami hits the nuclear power plant. Because of that people who lives nearby have to move since of the water that is contaminated by the nuclear power plant.

4. ACCORDING TO YOUR OPINION, IN ORDER TO PRODUCE ELECTRICAL ENERGY, WHAT IS THE BEST ENERGY THAT FITS WITH THE CURRENT SITUATION AND IS POLLUTION FREE?

The best way to produce electricity and its pollution free is Wind Energy or Solar Energy. Both wind and solar energy are pollution free because wind energy produces energy from wind that is received using a windmill that spins while solar energy uses solar panels to get energy directly from the sun. By using these alternative ways to get energy easily, there are also some advantages of using these alternative energy. for example wind energy; it needs lots of wind speed and it  generate a little energy. While solar energy; its low efficiency. it requires large areas of land.    

5. WRITE DOWN YOUR SUGGESTIONS IN ORDER TO PRODUCE A VERY HIGH TEMPERATURE, SO THAT A LARGE AMOUNT OF ELECTRICITY CAN BE GENERATED FROM THE USE OF SEA WATER.

By using nuclear energy. Since nuclear energy is caused by the splitting of the atomic nucleus, the  reaction is called fission. Fission is the splitting of a heavy nucleus into two lighter nuclei that releases a huge amount of energy and fusion is the process of joining the nuclei of atoms accompanied by huge energy release. The fuel for fusion is deuterium or heavy hydrogen which you can get from sea water. Sea water contains unlimited amounts of hydrogen. But we need at least 100 million degrees Celsius to join the nuclei of atoms which requires advanced technology.

     SOURCES OF ENERGY

• Non-Renewable Energy

A source of energy which is not renewable is the source of energy which cannot be regenerated when it is used. Examples of non-renewable energy is fossil fuel. Fossil fuel are also called conventional fuel.

• Renewable Energy

Source of energy which is renewable is the source of energy which can be regenerated when it is used up. Nowadays, renewable energy is used as an alternative energy to replace conventional energy and fossil fuels. the sources of alternative energy are, for example, wind energy, waterfall energy, solar energy, nuclear energy, tidal energy, geothermal energy, and biomass energy.

WIND ENERGY:

Wind energy is one of many renewable sources of energy, because it always available in nature. back then, windmills are used to grind and to pump water. Nowadays, windmills are used to drive electric generators to produce electricity.

WATERFALL ENERGY:

Moving water can rotate turbine which further produces electricity. There are Potential and Kinetic energy acting upon it to generate electricity in a hydroelectric power plant. An artificial waterfall can be built by constructing a dam. A dam can help to generate electricity in hydroelectric power plant.

SOLAR ENERGY

Solar energy is easy to get and pollution-free. there are two methods of collecting solar energy; they are a passive and an active method.

•  PASSIVE METHOD:

 Passive method has been used since a long time by the Romans to heat up their bathing water. Nowadays, glass windows are placed in buildings to get the warmth from solar energy.

• Active Method:

The active method, uses solar panels to collect and store solar energy. the solar energy panels transforms solar energy into thermal energy. Solar panels are made up of black plates covered by transparent glass or plastics.

NUCLEAR ENERGY

Hiroshima and Nagasaki were destroyed by an atomic bomb. that huge source of energy came from energy release generated by the splitting of the atomic nucleus. The reaction is called Fission. This fission produces a huge amount of energy called nuclear energy. Nowadays, nuclear energy is used for electric power plant, and usually called a nuclear power plant.

FISSION:

The operation of a nuclear power plant is based on fission. Fission is the splitting process of a heavy nucleus into two little nuclei.