[Physics Class Notes] on Difference Between Pound and Kilogram Pdf for Exam

Pounds and kilograms are both units for measuring mass. Pound refers to an imperial system of measuring weight or mass. Kilogram, on the other hand, was adopted under the SI or International System of Units in 1959.  

However, there are incremental differences when calculating mass in kilograms as opposed to the same calculation in pounds. How many kg in one pound is a common query for many individuals trying to compound the mass of an object from kilogram to pounds, or vice versa.

One Pound is Equal to How Many Kgs 

One pound is equal to just under half a kilogram. To be exact, 

1 pound = 0.453 kg

By this same equation, one can derive how many pounds in a kilogram.

1 kg = 2.204 pounds

Before proceeding to learn the difference between pound and kg, let us understand a bit more about kilogram and pound.

History of Kilogram 

A kilogram is referred to as the basic unit of mass in the metric system. 

In 1795, a kilogram was originally defined as the mass of one litre of water. It was the platinum Kilogramme des Archives that replaced it as the standard of mass in 1799. 

In 1899, it was superseded by a standard kilogram (also a solid cylinder), whose height was equal to its diameter, and was made of the same platinum-iridium alloy as the bar that was then used to be the standard for defining the metre. 

In 2011, the General Conference on Weights and Measures or CGPM came up with a proposal that focused on redefining the kilogram by a fundamental physical constant instead of a physical artefact. The Plank’s constant was chosen as the fundamental physical constant. This was done with the main aim of avoiding the issue of having the kilogram defined by an object that had a changing mass. And at the 2018 CGPM, the said proposal was accepted and was put to an application from May 2019. 

What is Kilogram?

Under the SI system of measurement, a kilogram is considered equal to the mass of one litre of water. Stored in a vault at the International Bureau of Weights and Measures, France, IPK is a standard Iridium-Platinum cylindrical figure that is exactly equal to 1 kg. To understand the relation between pound and kg, you should also learn more about a pound.

History of Pound 

​​The lbs meaning of weight comes from the Latin word “pondus” which happens to be the unit of weight. 

The term pound dates back a long time. It was first said to have originated as a result of Charlemagne’s reform with regard to currency in the Frankish Empire. 

In Mediaeval England, there were several derivations used of the libra (the libra is the Roman ancestor of the modern pound) vied for the purpose of general acceptance. Amongst the earliest of these, the Tower Pound (it is called the Tower Pound as its standard used to be kept in the Royal Mint in the Tower of London) was applied to certain precious metals as well as drugs and contained about 5,400 grains (o.350 kg) whereas the mercantile pound contained about 6,750 grains (0.437 kg). 

Now, the word pound that happens to be an English word, is connected to a lot of different countries. For instance, German Pfund, Swedish Pund, and Dutch Pond. All these countries are known to derive from a borrowing into Proto-Germanic of a Latin expression; the expression is lībra pondō wherein the adverb pondō means “by weight” and happens to be related to the noun pondus/weight; the expression as a whole, thus refers to “a pound by weight” 

What is Pound?

A pound is one of the units of measuring mass under the Imperial system. Other scales include stone and ounce. Abbreviated as ‘lb’ due to the pound’s association with the Roman Libra, this unit has several varieties in different countries.

The exact answer to how many kg in one pound is 0.45359237 kg. Nonetheless, remembering this figure is difficult, which is why most calculations consider 1 pound = 0.450 kg.

Multiple Choice Question – 1

Raj Buys 10 Pounds of Potato. How many Kg of potato did he buy?

1. 4.23 kg

2. 6.53 kg

3. 4.53 kg

4. 3.73 kg

Ans: (c) 4.53 kg

Differences Between Kg and Pound

Pounds to Kilogram Formula

Being able to answer how many kg in one pound is not sufficient. You should also be able to convert pounds into kilograms quickly, as well. To do so, simply multiply the mass in kg with 0.453. For example, 3 pounds will be equal to 3 x 0.453 kg.  

Kilogram to Pounds Formula

In a similar fashion, when converting mass from kilogram to pounds, multiply the weight in kg with 2.204.

Now that you know the difference between kg and pound, here is a quick exercise to solve.

Exercise – 1

Q. Shruti orders 45 pounds of cement for the construction of her home. However, she receives only 13 kg of cement. How many pounds of cement does she need to complete her order?

Solution: 

Method 1

Start by converting 45 pounds into kg.

Thus, cement ordered (in kg) = 45 x 0.453 = 20.38kg    

Shruti received 13 kg of cement from her order. Thus, cement still to be delivered is (20.41 – 13) kg. Therefore, she is yet to receive 7.38 kg of cement. 

Pounds of cement yet to be delivered = 7.38 x 2.20 = 16.236 pounds.

 

Method 2

This is the faster procedure, involving just one conversion.

Start by converting 13 kg into pounds.

Cement delivered = 13 x 2.204 = 28.65 pounds.

Cement to be delivered = 45-28.65 = 16
.35 pounds 

The calculation becomes extremely simple when one can remember the lbs to kilos formula.

One pound vs kg calculations can become easier with help from ’s wide array of tricks and tips. We even offer a app for students to ensure enhanced connectivity. Through this application, students can attend classes and learn more about particular chapters, topics and subjects.

Difference Between Mass and Weight

Did You know? 

The kilogram was said to be the last of the SI units that were defined by a physical artefact!