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 :)