Using a balance allows you to measure an object’s mass. This method works on the assumption that the acceleration due to gravity (g) is the same on both sides of the scale.
However, atomic and particle physics have found that different atoms and particles have the same chemical makeup but different masses. The metric system provides flexibility to accommodate these discoveries.
What is mass?
Basically, mass is a quantitative measure of an object’s inertia, or its resistance to change in velocity when a force is applied. It is one of the fundamental concepts in physics and is measured in kilograms (kg).
Weight, on the other hand, is an expression of the gravitational pull on an object and changes depending on where an object is in space. For example, your weight on Earth and Mars will be different, but you will still have the same mass.
Mass is also used in the atomic and molecular makeup of objects, and is often defined as the product of an object’s protons and neutrons, or its atomic number. Moreover, it is a key component of Newton’s Second Law of Motion: “force equals mass times acceleration.” It is also the basis of Einstein’s Mass-Energy Equivalence: E=mc2. The standardized unit of mass is the kilogram, introduced by the International Metric Convention in 1875. This prototype kilogram was based on a number of natural constants, including Planck’s constant and the gravitational constant.
Measuring mass
There are a few different ways to measure mass. One method is to use a balance or scale. This is the way most people weigh themselves. Another method is to subtract the weight of the container and then measure the mass of the sample. This is a more accurate method, but it is also more expensive than using a scale.
There is also a method that involves measuring the object’s density. The density of an object determines its inertia, so if you put two objects of the same size next to each other, the one with higher mass will accelerate slower. Other methods of measuring mass include calculating the force of gravity on an object and solving for its mass, using the principle of relativity.
In physics, the kilogram is the standard unit of mass used in the International System of Units (SI). The physical prototype kilogram was replaced with a new definition in 2019, but the kilogram is still an important part of our scientific vocabulary.
Using a balance
In the laboratory, balances are used to measure mass. They work on the principle that the gravitational force of an unknown object is proportional to its mass. The unknown object is weighed on one side of the balance and the standardized weights on the other. The balance can then determine its mass by comparing the force of gravity exerted on the standardized weights with the gravitational force of the object being weighed.
There are many different types of balances available today. They can be divided into two broad categories: precision and analytical balances. Precision balances are designed to weigh larger objects and can bear more weight than analytical balances. Analytical balances are typically closed models and can be used to weigh very small, dry chemicals and powders.
It is important to follow proper procedures when using a balance to measure mass. This will ensure accurate results. For example, never place a chemical directly on the balance pan. Instead, use a piece of weighing paper or a container. Also, do not touch the weighing surface with your hands. Moisture, dirt and grease will affect the weighing result.
Using a transducer
A transducer is an instrument that converts the change in a variable input into a machine-readable output signal. This can be done using a variety of signal formats, including current loops or analog voltages. The output from the transducer is usually given in a standardized format for easy computer automation.
The output of the transducer is often indicated by an input linear and tolerance range. The former guarantees the transducer linearity, and the latter indicates the maximum input value that does not cause the transducer to oversaturate.
A good method for locating the puncture point of an abdominal mass is to apply a small amount of pressure with the transducer, then mark the skin where maximal capsular distension occurs. This will ensure that the needle is positioned at the correct position to make a successful puncture. The same procedure can be used to locate the site of a hernia. Then, the needle can be inserted through that site.