General terms related to spherical mirrors: A mirror with the shape of a portion cut out of a spherical surface or substance is known as a...

General Terms Related to Spherical Mirrors

April 11, 2024**Measurement of Lengths: **In the olden days, the length of a foot, the width of a palm, etc., were used as units to measure length. One of the oldest ways to measure the length was ‘Cubit’. The length of the arm from the elbow to the fingertips is known as a cubit. These units changed from person to person that made the measurements non-uniform. In order to maintain uniformity in the measurements, standard units of measurements have been accepted worldwide.

**Learn About Conversion of Units of Length**

Length is the term used for identifying the size of an object or the distance from one point to another. Length is the measure of how long an object is or the distance between two points. It is used for identifying the size of an object or distance from one point to another. The length of an object is its extended dimension, that is, its longest side.

**Example:** The length of the ruler in the given diagram is \({\rm{24}}\,{\rm{cm}}{\rm{.}}\)

The table length can be measured by using the hand span.

Measurement of the length of objects is a part of our day to day life, and you can always perform these types of tasks in which you get to measure the length.

Measuring the length of any object with the help of measuring tools like a scale is known as measuring length.

**Example:** The length of a pencil and a crayon can be measured in inches using a ruler as shown below:

The height of the children can also be measured using a feet scale.

You can easily compare the lengths of two or more objects by just looking at them. Few examples are shown below:

As you can see, the length of the giraffe is tall, and the monkey is short.

The length of the given lamps in the diagram below is as tall, taller, and the tallest.

Long distances are generally measured in kilometres. A kilometre equals \(1000\) metres. The short form of a kilometre is written as \({\rm{km}}{\rm{.}}\)

\(1\,{\rm{kilometre}}\,({\rm{km}}) = 1000\,{\rm{metres}}\,({\rm{m}})\) or \(1000\;{\rm{m}} = 1\;{\rm{km}}\)

You can see the different units of length and their equivalent in the below-given table:

\(10\) Millimetres | \(=\) | \(1\) centimetre \(\left( {{\rm{cm}}} \right)\) |

\(10\) Centimetres | \(=\) | \(1\) Decimetre \(\left( {{\rm{dm}}} \right)\) |

\(10\) Decimetres | \(=\) | \(1\) Metre \(\left( {{\rm{m}}} \right)\) |

\(10\) Metres | \(=\) | \(1\) Decametre \(\left( {{\rm{dam}}} \right)\) |

\(10\) Decametres | \(=\) | \(1\) Hectometre \(\left( {{\rm{hm}}} \right)\) |

\(10\) Hectometres | \(=\) | \(1\) Kilometre \(\left( {{\rm{km}}} \right)\) |

Length is one of the most common measurements that we use in our daily life. It helps us tell how far away the nearest town is, the width of your fridge, or helps in understanding your height.

Measurement is used for measuring things or some amount of quantity. So, it is essential to measure certain things in a proper way like distance, time, etc., as they help us organise our time and lives accurately.

By measuring things or taking these measurements, you can better understand the accuracy of measuring. Measurements can also allow you to make the right decisions based on the outcome of the measurement.

By this reasoning, measurements are vital as they shape the way you think and interact every day.

The standard unit of the length based on the metric system is meter \(\left( {\rm{m}} \right).\) According to the length that needs to be measured, you can convert a meter into different units like millimetres \(\left( {\rm{mm}} \right),\) centimetres \(\left( {\rm{cm}} \right),\) and kilometres \(\left( {\rm{km}} \right).\)

Centimetres and millimetres are used to measure smaller lengths, and meters and kilometres are used in measuring the more extensive lengths like the distance between two places or cities.

Example: The length of the pencils can be measured in centimetres \(\left( {\rm{cm}} \right),\) while kilometres can measure the distance between two buildings or two places.

One hundred equal divisions of a meter give a centimetre. It is written as \(\left( {\rm{cm}} \right),\) and that is:

\(1\;{\rm{m}} = 100\;{\rm{cm}}\)

One thousand equal divisions of a kilometre give a meter \(\left( {\rm{m}} \right){\rm{,}}\) and that is:

\(1\;{\rm{km}} = 1,000\;{\rm{m}}\)

So, according to the conversion charts of length, the various units of lengths and their equivalents are written below:

A kilometre \(\left( {\rm{km}} \right){\rm{,}}\) meter \(\left( {\rm{m}} \right){\rm{,}}\) and centimetre \(\left( {\rm{cm}} \right)\) are often used as units of length.

Conversion of these units is done by using the below-given formula:

Additionally, in the conventional system followed in the United States, inches, feet, yards, and miles are used as the unit for length.

The relation between the customary units is shown below:

With the assortment of different units, the metric system seems quite logical. Compared to the customary system, converting units in the metric system is much easier than converting them in the customary system.

The United States is the last nation remaining that has not adopted the metric system. However, converting the units in the metric to the customary system is accessible using the given conversion.

\({\rm{1\, meter (m) = 39}}{\rm{.4\, inches = 1}}{\rm{.09\, yards;}}\)

\(1\,{\rm{yard}} = 0.92\;{\rm{m}}\)

\(1\,{\rm{centimeter}}({\rm{cm}}) = 0.39\,{\rm{inches;}}\)

\(1\,{\rm{inch}} = 2.54\;{\rm{cm}}\)

The word length is derived from the Middle English word ‘lengthe’ and the old English ‘lengou’, which means property of being extended or long in one direction. The metric system of measurement of length was first adopted from the French word, and currently, it is used by more than \(95\% \) of the world’s population.

*Q.1. Convert into centimetres: \(9\,{\rm{m}}\,30\,{\rm{cm}}\)*** Ans:** We know that \({\rm{1m = 100\;cm}}\)

\({\rm{9m}}\,30\;{\rm{cm}} = {\rm{9m}} + 30\;{\rm{cm}}\)

\( = 9 \times 100\;{\rm{cm}} + 30\;{\rm{cm}}\)

\( = 900\;{\rm{cm}} + 30\;{\rm{cm}}\)

\( = 930\;{\rm{cm}}\)

Hence, the required answer is \(930\;{\rm{cm}}.\)

*Q.2. Convert into centimetres: \(6\,{\rm{dm}}\,5\,{\rm{cm}}\).*** Ans:** We know that, \({\rm{1dm = 10\;cm}}\)

\(6\,{\rm{dm}}5\;{\rm{cm}} = 6\,{\rm{dm}} + 5\;{\rm{cm}}\)

\( = 6 \times 10\;{\rm{cm}} + 5\;{\rm{cm}}\)

\( = 60\;{\rm{cm}} + 5\;{\rm{cm}}\)

\( = 65\;{\rm{cm}}\)

Hence, the required answer is \(65\;{\rm{cm}}.\)

*Q.3. Suppose the height of Ria’s father is 50% more than the height of Ria. If Ria is 52 inches, then the height of the father is?*** Ans:** Given the height of Ria \(=52\) inches.

The height of the father is \({\rm{50\% }}\) more

Height of father \({\rm{ = 52 + 50\% }}\) of 52

\( = 52 + \frac{1}{2} \times 52\)

\( = 52 + 26\)

\(=78\) inches

\(∴\) The height of the feather is \(78\) inches.

*Q.4. If Jamie covers 0.5 yards in one step, how much distance will he cover in 50 steps?*** Ans:** Distance covered in one step \(=0.5\) yards

Total steps were taken by Jamie \(=50\)

Total distance covered by Jamie \(=0.5×50=25\) yards.

\(∴\) Jamie covered \(25\) yards.

*Q.5. The rectangle field is to be fenced by a single iron rope. If the measurement of the field’s length is 100 yards and the breadth is 80 yards, how much fencing rope will be required?*** Ans:** Dimensions of the rectangular field are given as:

Length \(=100\) yards

Width \(=80\) yards

The perimeter of the field \(=2(100+80)\)

\(=2×180=360\) yards

Hence, the length of the rope required is \(360\) yards.

The topics covered in the given article are the length, its measurements, units, and examples. Then, we discussed the unit of measurement of length, followed by uses and importance of measurement of length. Finally, we glanced at the standard unit of measuring length. Then we have provided you with the solved examples followed by a few frequently asked questions.

**Learn About Instruments for Measurement**

*Q.1. What are the measurements of length?*** Ans:** Measurement of the length of objects is a part of our day to day life, and you can always perform these types of tasks in which you get to measure the length. Measuring the length of any object with the help of measuring tools like the scale is known as measuring length.

*Q.2. What is the essential measure of length?*** Ans:** In the International System of Units \(\left( {{\rm{SI}}} \right){\rm{,}}\) the base unit of length is the metre \(\left( {{\rm{m}}} \right){\rm{.}}\) The millimetre \(\left( {{\rm{mm}}} \right){\rm{,}}\) centimetre (cm) and kilometre \(\left( {{\rm{km}}} \right){\rm{,}}\) derived from the metre, are also commonly used units in the measurement of length.

*Q.3. What are the three various methods to measure length?*** Ans:** The three different methods to measure the length are given below:

1. The first method is to measure using the handspan of the cubit that is the length between the thumb and little fingertip when stretched.

2. The second method is to measure by using the arm length between the shoulder and tip of the fingers.

3. The third method is to measure by using our footstep that is the length between the thumb and the foot’s heel.

*Q.4. What is the standard unit of measuring length?*** Ans:** The standard unit of the length based on the metric system is the meter \(\left( {{\rm{m}}} \right){\rm{.}}\) According to the length that needs to be measured, you can convert a meter into different units like millimetres \(\left( {{\rm{mm}}} \right){\rm{,}}\) centimetres \(\left( {{\rm{cm}}} \right){\rm{,}}\) and kilometres \(\left( {{\rm{km}}} \right){\rm{.}}\)

*Q.5. What are the two types of measurement?*** Ans:** The two types of systems of measurement are given below:

The first one is the Metric (or decimal) system and

The second one is the US standard system.

*Q.6. What tools are used to measure the length?*** Ans:** The tools used to measure length are ruler, vernier calliper, micrometre, screw gauge, measuring tape etc. Vernier callipers and micrometre screw gauges are more precise and can measure the diameter of objects like pipes and wires.

*Now you are provided with all the necessary information on the measurement of lengths and we hope this detailed article is helpful to you. If you have any queries regarding this article, please ping us through the comment section below and we will get back to you as soon as possible.*