A woman weighs 125 pounds.
Use this relationship in your calculation: 2.205 lb = 1 kg
a) How many kilograms is this weight?
b) How many grams is this weight?
The correct answer and explanation is :
To convert weight from pounds to kilograms and grams, we’ll use the relationship you provided: 2.205 lb = 1 kg.
Part a) Converting Pounds to Kilograms
To find how many kilograms 125 pounds is, we can use the conversion factor:
[
\text{Kilograms} = \frac{\text{Pounds}}{2.205}
]
Substituting 125 pounds into the formula:
[
\text{Kilograms} = \frac{125}{2.205} \approx 56.69 \, \text{kg}
]
So, 125 pounds is approximately 56.69 kilograms.
Part b) Converting Pounds to Grams
To convert the weight from pounds to grams, we first need to convert pounds to kilograms (as done in part a), and then convert kilograms to grams.
We know that:
[
1 \, \text{kg} = 1000 \, \text{grams}
]
So, to convert kilograms to grams, we multiply the number of kilograms by 1000:
[
\text{Grams} = 56.69 \, \text{kg} \times 1000 \, \text{g/kg} = 56,690 \, \text{g}
]
Thus, 125 pounds is approximately 56,690 grams.
Explanation
To understand these conversions, let’s break it down:
- Pounds to Kilograms: The relationship (2.205 \, \text{lb} = 1 \, \text{kg}) means that for every 2.205 pounds, you get 1 kilogram. To convert pounds to kilograms, we divide the number of pounds by 2.205. This gives us a weight in kilograms, a metric unit commonly used around the world, except in the United States where pounds are the norm.
- Kilograms to Grams: Since the metric system is based on powers of 10, converting from kilograms to grams is straightforward. For every kilogram, there are 1000 grams. Therefore, multiplying the weight in kilograms by 1000 gives us the equivalent weight in grams.
These conversions are part of the broader system of unit conversions that help in scientific, medical, and everyday contexts to standardize measurements globally. In everyday life, it’s useful to know how weight measured in pounds translates to the metric system, especially if you’re traveling, buying items overseas, or reading scientific data.
