The simplest definition of weight suggests that it is an indicator of how heavy or light an object is. When you find it relatively easy to pick up an object, you say that it is light in its weight. On the other hand, you often label an object as heavy if you are unable to lift it off the ground? But is that all there is to the term ‘weight’? Or is there much more to it?
Also, how do we express weight mathematically? Do you use a unit of weight or mention the numerical value? Read on to find out more about it!
Merely speaking, the weight of an object is the force with which the gravitational field of the Earth pulls it towards the surface. In other words, weight refers to the force at which a body accelerates towards the surface of Earth because of its gravitational pull.
As you know, anything suspended in air falls to the ground. The reason for this phenomenon is that this planet possesses a field of gravity which enables an object to fall on the ground. For instance, when you hold a ball or an egg higher from the ground level and let go of it from your hold. You witness that it immediately drops on the ground.
Therefore, the SI unit of weight aims to express the numerical value of the force that attracts an object towards the ground.
Consider that an object whose mass is 1 kg falls vertically on the ground under a gravitational force of 1 m s-2. Now, if you are wondering what is the unit of weight, it is the product of all these components.
Therefore, weight = mass X gravity.
In this case, weight of the object is –
1 kg X 1 m s-2 = 1 kg m s-2.
Thus, the standard unit of weight is kg m s-2. However, you can also express it in terms of Newton (N). This very unit calls after the famed scientist Isaac Newton who first discovered gravitational pull.
Therefore, Newton (N) refers to the SI unit of weight.
Moreover, other weight measurement units involve the following –
Dimensional Unit of Weight – MLT-2, where M stands for mass, L refers to distance, and T is time.
CGS Unit of Weight – Dyne. CGS unit implies centimeter-gram-second, where weight becomes 1 g cm s-2. You can also arrive at dyne when you divide 1 Newton by 10000.
Base Unit of Weight – The base unit is the one that we have already discussed earlier. Therefore, it is kg m s-2.
Solve the Following Problems by Yourself
Object A has a mass of 5 kg. On the other hand, the gravity working on it is 10 m s-2. Find out what is the standard unit of weight is in the case of object A.
The unit of weight in SI system for an object X is 150 N. If mass of object X is 50 kg, find out the gravitational pull working on it.
You might often come across people who use the terms ‘weight’ and ‘mass’ interchangeably. However, these two terms have fundamental differences in what they mean scientifically. In simple terms, mass refers to the amount of matter that an object possesses.
On the other hand, weight implies the force with which the object travels towards the surface of earth. It suggests that weight differs for an object as per alterations in the gravitational pull.
For instance, the mass of an astronaut remains the same on both earth and moon. Yet, the gravitational pull is 6 times lesser on the moon than on Earth. As a result, an astronaut will weigh 6 times less on the moon than on Earth.
Now that you know what the unit of weight is, follow through the related topics to understand this concept even better. You can also download our Vedantu app to experience personalised learning online along with highly interactive sessions.
1. What is Weight?
Ans. Weight is the force with which the earth pulls an object towards itself due to its gravitational force.
1. What is the SI Unit of Weight?
Ans. SI unit of weight is Newton (N) which can be defined as kg m s-2.
3. What is the Base Unit of Weight?
Ans. The base unit of weight is kg m s-2, where kg stands for kilogram, m denotes metre and s stands for seconds.