Weight or mass?

 I believe each of us see the weigh at least two months or every week?. Then when someone see their  weight and shock to see her weight go up then we'll hear "oh no, Imy weight gained 5 kg". Then when we shop at traditional markets, when order groceries we usually say, "buy chicken half kilogram weight please?". Then what's wrong with 2 sentencesabove ?. Let's look at these sentence, there are physical quantities and units of weight and kilograms. Are they the right pair of quantity and unit? Let's follow the explanation this time. :)

Magnitude is something that can measure and have  value. Magnitude divided  into two principal amount and the derrivativ quantity. The amount of the principal amount of a unit is determined before. There are  7 scale that is included in basic quantity :

1. Length (l) with units of meters (m)

2. Mass (m) with unit Kilogram (kg)

3. Time (t) with units of seconds (s)

4. Strong Flow (i) the unit Ampere (A)

5. Temperature (T) and Kelvin (K)

6. The light intensity (I) with unit Candela (Ca)

7. The number of units Molukel with Mole (mol)

Furthermore, the magnitude of the derivative is the amount of other quantities are derived from the principal amount. Inordinate amount of derivatives in their daily lives, for example, such as weight (N), velocity (m / s), pressure (Pa), dlll. As we saw above, both the principal amount and the amount of its derivatives have the units of each,. We can not pair with a long second unit.

Well, from the explanation above, we can see the error on our daily two statements above. Apparently nit of weight  not kilogram but newtons, and quantity  that has the unit of mass is the kilogram. So now we know that we  calculate everyday  is the masses who have the units of kilograms and is one of the principal amount of members, not weight.

We can express the amount  of weigh it , but we have to adjust again the value and units. Weight is the gravitational constant mass multiplication of objects. So the weight of the object may change change if the value of the acceleration of gravity changes. The formula weight is:

W = m x g

With w (N) is the weight, m ​​(kg) is the mass and g (m / s squared) is the acceleration of gravity. For example, we consider our mass of 45 kg, berapkah weight if known gravity 9.8 m / second squared?

W = m x g

W = 45 kg x 9.8 m / s squared

W = 441 N

From the calculation above  we can say that the weight of us is  441 N. But this value will change if we were on the moon, because the moon's gravitational constant value different from the earth. So the value of 441 N and is only valid if it is measured on earth.

So, the conclusion is weight is different from masss, because weight depend on gravitational constant and mass is constant. And remember 45 kg is not your weight but your mass.

Furthermore, let's prediction, how heavy an object if we take it to a vacuum?. I think a body would have the different weight values ​​as well as the vacuum has an individual value of the gravitational constant. Let us remember that the vacuum is a room with no air, not space without gravity, so the vacuum still have the value of the gravitational constant and can be calculated by weight.

Hope ituseful :)

Calculating Acceleration

The meaning of acceleration     

In everyday language, the term accelerating means “ speeeding up “. Anything whose speed is increasing is accelerating. Anything whose speed is decreasing is decelarating. To be more precisi in our definition of acceleration, we should think of it as changing of which is changing its direction has acceleration. Because acceleration is linked to velocity in this way, it follows that is a vector quantity. Example of objects acceerating is A car speeding up as it leaves the town, the driver presses on the accelerator pedal to increase the car’ velocity.

Calculating acceleration

          The acceleration of something indicates the rate at which its velocity is changing.  Languange can get awkward here. We might say “ the sprinter accelerates faster than the car”. However, “faster” really means “greater speed”. So it is better to say  “ the sprinter has a greater acceleration than the car. Acceleration is defined as follows :

                   Acceleration = rate of change of velocity

                   Acceleration =  Change in velocity / time taken

                                                

So to calculate accelaration a, we need to know two quantities, the change of velocity  delta v and time taken delta t.

                   a = v / t

Sometimes this equation is writte differently. We write u for the initial velocity and v for the final vlocity ( because u comes before v in the alpabet). The moving object accelarates from u to v in a time t ( this is the same as the time rpresented bg delta t above). The accelerationis given by the equation :

                   a = v – u / t

                           

Example

1.     Leaving a bus stop, the bus reaches a velocity of 8.0 m/s after 10 s. Calculate the accelaration of the bus.

Step 1 : Note the bus initial velocity is 0 m/s. Therefore :
             change in velocity ( delta v ) = ( 8.0 - 0)m/s

             Time taken ( delta t ) = 10 s

Step 2 : Subtitute these values in the equation for acceleration :

              acceleration a = delta v/ delta t = 8.0 / 10 = 0.8 m/s square     

2.    A sprinter starting from rest has an acceleration of 5.0 m/s square during the first 2.0 s of race. Calculate her velocity after 2.0 s.

Step 1 : Rearranging the equation a = v - u / t , gives : v = u + at

Step 2 : Subtituting the values and calculating gives :

              V = 0 + ( 5.0 x 2.0 ) = 10 m/s

Hope it usefull :)

Playing Magic with Magnet

I believe every one in this world ever heard magnets. As we know magnet can inerect with another things by touching them. Can  magnets interact without touching the object? Scientists have try it  through air, water, glass, and other objects. Now we will study how can it happend? Check it out J

What You Need?

1.A bar magnet or magnet U

2. Paper Clip

3. Iron Powder or other metal objects from

4.Scotch Tape

5. Paper

6. Glass

7. Water

8. String

Try These:

1.     Tie the paper clip to the end of the string. Then attach the other end of the string with tape on the table or floor. Slowly lift the magnet towards the paperclip until it attracted. Be careful, do not get stuck the magnet to paper clips. Then try lifting magnet upwards slowly, try keep the distance of paper clip and magnet distance is always the same, whether the paper clips will be brought up to follow the magnet?

2.     Place the iron powder into the glass. If no try to find objects made of iron like a nail. After that, hold the magnet from the outside of the glass. Is there iron  in a glass could be attracted by a magnet?

3.   Now, pour water into the glass containing iron powder earlier. Then try to hold the magnet from outside the glass. This time the iron powder is attracted by a magnet? When finished, discard the water and pat dry with a tissue iron powder to avoid rusting.

Result

1.     The paper clips will brought up to follow the magnet

2.    Iron in the glass attrached by magnet

3.    Iron in the glass still attrached by magnet

Facts about Magnets:

After the experiment, we can see the magnets can attract objects made ​​of iron, even though there are medium such as air, water, paper, and glass. So the magnet can attract iron without direct contact with the iron. But the medium is not too thick for small magnet.

Hope it useful :)

Why when we turn off the televison the lamp still on?

Have you ever torn off one lamp in your house? What happend to other lights lamp? Is it turn off too?. The answer is no, the other lamp will not turn off too. Why it can be happend?, it is because our electricity in home using parallel circuit. To make you easier understand this concep, now i will give you a small experiment to proove that, check it out  :).

Required materials : 1. Two flashlight bulbs with sockects

                               2. Dry cell

                               3. Half a meter copper wire

                               4. Switch

                               5. Scissor

Step by step procedure :

1.    Cut the wire into five parts by scissor. Then strip about ¹/₂ inch (1.25 cm) of insulation from each end of the wires.

2.    Attach a wire to the positive side of the dry cell and connect the other end to the left side of a light bulb

3.    Attach another wire to the negative side of the dry cell and connect it to the switch

4.    Get another wire and conncet to the switch to the right side of the light bulb

5.     Add one more bulb to the setup by connect another wire to the left side of the first bulb and connecting the other end on the left side of the second bulb

6.    Connect another wire to the right side of the first bulb and connect it to the right side of the second bulb. Caution : Do not leave the wires on the screws for more than 5 to 6 seconds. The bare wire and lamp can get hot enough to burn you. Allow them to cool before touching them. The circuit  picture :

7.    See what happend when to the fiirst bulb when the second bulb added.

Result:

The adding of the second bulb is not affect to the brightness of the first bulb. The connection was not broken, the first buln is still on and light.

Why?

The electric current has more than one path to follow through the connected lamps in this experiment, so the circuit formed what is called a parallel circuit. The arrows in the electrical schematic in Figure 18.2 indicate the movement of the current (e') away from the negative terminal of the battery through the bulbs, then back to the positive terminal of the battery. At junction A (one of the screws on the side of lamp base 1), the current divides before moving through the lamps. Then the current recombines at junction B (one of the screws on the opposite side of lamp base 1) and returns to the positive terminal of the battery. The facts that the lamps are identical and glow with equal brightness show that the same amount of current reaches both lamps. This way, it is better than series circuit since the devices can be switched on and off separately without breaking any circuits and best circuit at home.

Ecstasy? It Make You Moving All The Time

Ecstasy??
I believe every one in tihs worl ever heard about this word.

Ecstasy ia one of anasthetic that made ilegally in a labotratorium in tablet or capsule form. Picture above is the example of ecstasy. Ecstasy is part of drug in psikotropika. Ecstasy make the user of Ecstasy has uncontrolled energy and also can fell high dehidration. That’s why the effect of ecstasy make our body always moving.

Immediate effects

Many people have experienced the following effects soon after taking ecstasy:

·         increase in confidence;

·         feelings of well-being;

·         feelings of closeness to others, hence the term ‘love drug’;

·         anxiety;

·         dilated pupils;

·         jaw clenching, teeth grinding;

·         increase in heart rate, body temperature and blood pressure;

·         nausea;

·         loss of appetite; and

·         sweating.

Higher doses

Higher quantities don't appear to enhance the desirable effects and may cause:

·         convulsions (fits);

·         vomiting;

·         floating sensations;

·         irrational or bizarre behaviour; or

·         hallucinations.

Overdose

Overdose from ecstasy can occur. It is usually characterised by very high body temperature and blood pressure, hallucinations and an elevated heartbeat. This is especially dangerous for those who have an existing heart condition or breathing problems, and for people with depression or other psychological disorder.

Death

Although it is difficult to determine the exact number of ecstasy-related deaths that have occurred, the toxic effects of ecstasy that can lead to death include the following.

·         Heart attack.

·         Brain haemorrhage.

·         Blood clotting.

·         Kidney failure.

·         Overheating: the combination of taking ecstasy with prolonged and vigorous dancing raises the body temperature to dangerous levels. Because it is often taken in hot, humid venues the risk of death by overheating (hyperthermia) is further increased.

·         Drinking too much: several deaths have occurred from dilutional hyponatremia — a condition whereby a person’s brain swells from excess fluid intake, inducing a coma.

Long-term effects

Research indicates that few people tend to use ecstasy for a long time. This is possibly due to the severity of undesirable effects, which tend to increase the longer ecstasy use continues, while the pleasurable effects diminish. A person taking ecstasy regularly may find that they are not eating or sleeping enough and are neglecting their health. They may become ‘run down’, have reduced energy levels and be more susceptible to colds, 'flu and infections.

Currently, much research is being undertaken to investigate the effects of ecstasy on the brain. There is limited evidence suggesting that ecstasy causes damage to some parts of the brain.

For more information, please click on the Australian Drug Foundation's DrugInfo Clearinghouse web site link below.

 Resource:

http://www.drugabuse.gov/publications/teaching-packets/neurobiology-ecstasy/section-iii/5-long-term-ecstasy-use-may-impair-memory

http://terselubung.blogspot.com/2011/10/efek-efek-mengkonsumsi-pil-ekstasi.html

http://www.mydr.com.au/addictions/ecstasy-effects-on-the-body

Sesungguhnya

Tak ada sedikitpun niatku

Untuk memasang kembali kaca spion di perjalanan merah jambu ini

Untuk mengintip kembali jalan jalan sebelum sampai kesini

Yang sangat menjanjikan kebahagiaan hidup ini

Bukan aku yang memasang kaca spion itu, kaca itu tiba tiba terpasang kembali kala terlintas deretan huruf membentuk sebutanmu

Akupun tak ingin terlihat seperti lemahnya kapas kala terkena tiupan angin

Akupun ingin menjadi batu karang yang hitam pekat, garang dan kuat

Tetapi aku hanyalah potongan tulang rusak yang mudah sekali rapuh

Aku rapuh karena aku hanya potongan yang belum menemukan pasangannya

Asal kau tahu, mungkin aku aneh, tapi ketika bagian merah jambu dari ku telah kau sentuh, tak semudah itu aku menghapusnya

Kau tahu, sulit sekali, telah kutemukan berbagai macam penghapus, tetapi tak ada yang bisa menghapus sentuhan yang telah kau berikan kepda bagian merah jambu ini.

Kala kulihat kau tertawa riang dengan gagahnya, aku meringis, serasa ada pisau pisau halus yang menyayatku, meyentakku

Bukan, bukan aku sedih melihat kau bahagia, tapi aku miris, miris mengapa aku tak jua kunjung sembuh dan bahagia

Kau orang yang kueja dengan sayang

Terkadang, ingin sekali ku membenci mu, tak menganggap kau ada, ataau bahkan tak pernah ingat kau ada.

Tapi dan lagi lagi tapi, itu bukanlah hal mudah hai orang yang kueja dengan sayang

Sampai sekarang, telah beralalu berpuluh puluh malam, kau tetap di bagian merah jambu ini. Hanya kau di bagian merah jambu ini

Maafkan aku, ternyata luka yang kau berikan di bagian merah jambu ini, tertutup oleh besarnya bekas sentuhan yang telah sebelumnya kau berikan

Maafkan aku, ternyata aku masih dan terlalu...

Kinetic Energy

                                                                  Kinetic Energy

First Definition for Kinetic Energy

When something is in motion it is said to have kinetic energy.

Formula for Kinetic Energy

For an object that is moving the kinetic energy equals one half times the mass of the object times the square of the speed of the object. In symbols:

E_K = (1/2)mv²

Example Calculation for Kinetic Energy

How much kinetic energy does an object have if its mass is 5.0 kg and it is moving at a speed of 4.0 m/s?

EK = (1/2)mv2	Formula for kinetic energy.
EK = (1/2)(5.0 kg)(4.0 m/s)2	Plug in values for mass and speed.
EK = 40 J	Kinetic Energy equals 40 J.

Example Kinetic Energy in Daily Life

©   Orbital motion: moons about the planets, or the planets around the sun. The motion of the stars in a galaxy, orbiting satellites and space vehicles. 

©   Random linear motion: On a molecular level, vibrations of molecules, gas molecules bouncing around a     room.

©   Rotational or torquing motion: spinning flywheels, rolling balls or wheels 

©   Projectile (parabolic) motion: a fired bullet, a thrown ball, a boy jumping 

©   Linear motion: running, bowling, aircraft in flight, a moving car or train, a boy skateboarding

    The Picture above is one of example Kinetic Energy. The roller Coster has the higest value of kinetic energy in the higest position.

      The picture above is also one example of kinetic energy. The Ball started have kinetic energy when it fall down from mountain

Thank You. Hope it useful :)