Weight is the measure of how heavy an object is. Weight is measured in standard customary units.
The mass of an object is the amount of material it contains. Mass is measured in standard metric units.
For everyday purposes, when you're on the surface of the earth, the difference is not important. But if you measure something on another planet, its mass will be the same as it is on earth—but its weight will be different. (Weight depends on gravity, and gravity is different on other planets! This is why when you're floating in space, you're weightless. You still have mass, though,)
Metric Units
The gram and kilogram are two units used to measure mass in the metric system .
From the gram, we get the rest of the metric units using the standard metric prefixes.
| Milligram(mg) | gram or gram |
| Centigram(cg) | gram or gram |
| Decigram (dg) | gram or gram |
| Gram(g) | milligrams |
| Dekagram (dag) | grams |
| Hectogram (hg) | grams |
| Kilogram (kg) | grams |
| Metric ton(t) | kilograms |
A paper clip has a mass of about gram.
A liter bottle of water has a mass of kilogram (plus a little bit extra for the plastic).
U.S. Customary Units
The system for measuring weight (not mass) in the customary system is based on ounce, pound, and ton. The basic unit of weight is a pound(lb).
An ounce is the smallest unit of weight. A strawberry has a weight of about ounce.
A car has a weight of about tons.
To convert from one unit to another, we can use unit analysis . For example, a truck weights pounds. How many tons is this?
We know that .
To convert pounds to tons, you can divide by .
.
Note:
(a) To convert from larger units to smaller units, multiply by the appropriate unit ratio.
(b) To convert from smaller units to larger units, multiply by the reciprocal of the appropriate unit ratio.
(c) Multiplying or dividing by a unit ratio is mathematically equivalent to using a proportion to convert between units of measure .
I'm an expert in physics and measurement concepts, particularly in the realm of mass and weight. My knowledge extends to the fundamental principles of these concepts, and I can provide a comprehensive understanding of the distinctions between mass and weight, as well as their measurement units.
Now, let's delve into the concepts mentioned in the article:
1. Mass and Weight:
- Mass is the amount of material in an object, measured in standard metric units.
- Weight is the measure of how heavy an object is and depends on gravity. It is measured in standard customary units.
- On Earth's surface, the mass and weight of an object are practically equivalent. However, on different planets with varying gravity, the weight will differ while the mass remains the same.
2. Metric Units:
- Gram (g) and kilogram (kg) are units used to measure mass in the metric system.
- Other metric units include milligram (mg), centigram (cg), decigram (dg), dekagram (dag), hectogram (hg), and metric ton (t).
- The relationships between these units are defined by standard metric prefixes.
3. Example Mass Measurements:
- A paper clip has a mass of about 1 gram.
- A 1-liter bottle of water has a mass of 1 kilogram, with additional weight accounting for the plastic.
4. U.S. Customary Units:
- The customary system measures weight using ounces, pounds, and tons.
- The pound (lb) is the basic unit of weight, with 1 lb equal to 16 ounces.
- 1 ton (T) is equivalent to 2,000 pounds.
5. Unit Conversion:
- Unit analysis and proportions are used for unit conversion.
- For example, to convert pounds to tons, you divide the weight in pounds by 2,000.
6. Conversion Tips:
- To convert from larger to smaller units, multiply by the appropriate unit ratio.
- To convert from smaller to larger units, multiply by the reciprocal of the unit ratio.
These concepts are fundamental in physics and measurement, providing a solid foundation for understanding mass, weight, and their respective units in both the metric and customary systems. If you have any specific questions or need further clarification on any of these topics, feel free to ask.
