# Question #01ea1

##### 1 Answer

Because it's practical to ignore the *gravitational acceleration* in everyday activities.

#### Explanation:

The **weight** of an object is simply a measure of the **force** the object has as a result of gravity.

The **mass** of an object can be though of as the amount of *matter* that respective object has.

The weight of an object is actually a vector quantity. The *magnitude* of that vector is the product between the **mass** of the object and the *gravitational acceleration*,

#W = m * g#

As you can see, the only difference between the mass of an object and the *magnitude* of its weight is the gravitational acceleration,

This means that for most everyday activities and situations, the difference between the weights of two objects will actually be equivalent to the difference between their two masses.

Let's say that you put an object on a scale and read its weight to be

In this case, the word "weight" is used correctly, but the value that's being read is actually *interpreted* as **mass**, that's why it uses *kilograms* instead of *Newtons*.

If the scale were to give you the weight in *Newtons*, then you would have to get the mass of the object by dividing that weight by the value of

#m = W/g = "9.81 N"/(9.81"m"/"s"^2) = "1 kg"#

Now, although this is the **correct** approach, it is not very practical for *everyday situations* because the value of

Moreover, your body is so accustomed to the value of *same value* of

So, as a conclusion, everyday activities *do not require* a distinction between weight and mass, which is why our scales measure weight but use the units of mass to express it.

If *practical* to use mass and weight interchangeably.