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How to Find The Mass of an Object

You might have a physics or physical science class in middle school, high school, college, or even have to find the mass of an object at work. Whatever your reason is for needing to find out this value, you must get an accurate reading of the mass that you are trying to figure out. To get a good reading, you will need to follow three steps.

First, use your scale or balance to find the mass of the object you are trying to measure.  Make sure you know how to use your scale or balance properly.

Second, find the weight of the object on a scale. The easiest way to do this is to put it in a container that weighs before and then weighs that container again. Subtract the weight of that container from the initial weight you got, and then you have your answer.

Third, take both values you just found and divide them to get your mass! 

And there you found how to find the mass of an object!

How to Find The Mass of an Object

What is Mass?

Ask a person on the street what mass is, and they will likely be able to tell you that it is a measure of how much “stuff” an object contains. Unfortunately, further explaining the concept usually results in statements about weight being somehow related to mass, leading some people to believe that the two terms are interchangeable. In reality, however, “weight” and “mass” are two different concepts that can easily distinguish by applying Newton’s Second Law F=ma to the following example:

Consider a person of mass 100kg walking on the surface of the Earth. That individual exerts a force (F) on the Earth’s surface to walk around (a). If you were to weigh (F) that individual using a bathroom scale, you would see that they exert roughly 10 Newtons of force. If we had measured the person’s mass instead of weight, we would find out that they only have a mass of 70kg. This demonstrates how “weight” is not equivalent to “mass” and that they are independent of one another.

Why Finding the Mass of an Object is Important

Why is finding the mass of something important? Well, it might seem like a straightforward thing, but there are quite a few reasons. For one thing, it helps determine size. If you know the mass of an object, then you can find its radius by multiplying that number by 2*3.14.

This is helpful when dealing with large objects because it lets you find out how far apart things need to be on a large scale. Another reason why finding the mass of an object is essential is that it allows you to determine how much gravitational force could exert on it.

So, for example, if you know the mass and the radius of planet earth, and you also know its density, then you can find out how much gravitational force it exerts by using the equation:

Gravitational force = (Mass of an object x Mass of an object) / ( Radius squared)

Formula for Mass

Formula for mass is-

Mass = ρ × v


ρ = density and

v = the volume

Formula for weight mass is-

m = w / g


w= weight

m = mass

g = gravity

How to Calculate and Measure Mass

There are different ways to measure mass, all based on some physical laws. The International System (SI) is using globally, except for the United States and a few other countries that still use British Imperial units.

The most common way to calculate mass is via weight, but this may be confusing since weight depends on where you are and on your local gravitational field. Therefore, weight is calculating by multiplying the mass of an object with a number that represents the force of gravity pulling on the object at a specific location, which depends on its elevation above sea level. This value is calling g-force or gravitational acceleration. The most commonly used units for g-force are 1 g = 9.80665 m/s² or, equivalently, 1 kg·m/s².

What is a Gravitational Constant and How Does it Relate to Finding the Mass of an Object?

A gravitational constant (G) is simply the number that relates force and mass. It was first defined by Sir Isaac Newton when he proposed his universal law of gravitation. If you’ve ever heard the term F = ma, then this is exactly what it’s referring to! This number (G) has the symbol G and is also known as “Newton’s Constant” or “Big G.”

G = 6.67 x 10 -11   Nm 2 / kg 2  (That was a mouthful!) This number relates to how much force you need to apply to an object for it to accelerate by 1 m/s every second.

For example, if you were to drop a rock (mass = 10 kg) off the side of your building (height = 200 m), then it would be accelerating at 2 m/s every second. Imagine having to push on that rock with only an ounce of force; that’s how much force that rock would exert on the Earth.

This means that if you want to find an object’s mass (weight), you can multiply its gravitational constant by its height!

The Difference Between Mass and Weight

how to find the mass of an object

The difference between mass and weight can easily explain by a simple explanation of the two.

Mass is the amount of matter something contains, weight is how heavy something is. These are not to confuse as they are both very different things with only similar definitions.

The mass of an object does not change no matter where you go or where you are. If an object is placing on the moon, it will still have the same mass as when placed on earth. This is because a body’s mass does not change based on location or environment, but its weight is greatly affecting by these factors.

Weight is the amount of force that gravity exerts upon an object. The weight of an object is determining based on the mass and the acceleration that gravity is exerting upon it at a specific location, or if you will, point in space. 

How to Find the Volume of an Object

To find the object’s volume, one must measure its cross-section (2r in this case) and multiply it by the depth. This is because “the volume of a solid is equal to the product of its cross-sectional area and its depth.” Using that method, you can solve it like this:


V = 6 cubic units.

How to Find the Density of an Object

Density is defining as an object’s mass divided by its volume. That is d = m/v in equation form, where d denotes the density, m is the mass, and v denotes the object’s volume. The standard units are kilograms per cubic meter.


How to Calculate Mass in Physics?

Mass is the most fundamental feature of matter and one of the primary quantities in physics. Mass is defining as the volume of mass contained within an object. The kilogram is the SI unit of mass (kg). Formula of mess is
Mass = volume × density
You can calculate any objects’ mass with this equation.

How to Find the Mass of an Object with Density and Volume?

The formula for mass is volume × density. So, if you know any object’s density and volume, multiply these two numbers to find the mass.

How to Calculate Mass from Weight?

Formula , (M = W ÷ G).

So if someone weighs 70 kilograms and the acceleration due to gravity is 9.8 meters/sec2, then the object’s mass equals. 

Mass = Weight ÷ G

Mass = 70 ÷ 9.8 = 7.1 kg

Weight doesn’t have units since it represents a ratio of forces. In this case, one force is causing by gravity, and the other is causing by whatever is being weighed.

How to Find Mass with Force and Acceleration?

One of the most common physics problems is how to find mass using only two measurements.  The question typically asks for the unknown object’s mass in kg, given that it is known that some force acts upon the object and that it experiences a certain acceleration due to this force.  A simple equation involving these two measurements may be used to solve this problem. 

The equation is:

F = ma

Where F is the force measured in Newtons (N), m is the mass of the unknown object in kilograms (kg), and a is its acceleration in meters per second squared (m/s²).


Learning about mass is important because it can help you find the weight of an object and know its density. I hope you got everything you need to know about how to find the mass of an object, why it’s essential, and how to find it. You can now confidently measure any objects’ weight by following these simple equations.