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# Peta|Definition & Meaning

## Definition

**Peta** is a decimal unit **prefix** meaning 1 **quadrillion** (10^{15}). It is denoted by P. **Peta** was added to the **international** **system** of **units** (SI) in 1975. **Peta** is used as a **prefix** in place of the fifth power of 1000. In **physics**, instead of multiplying a number by 1,000,000,000,000,000, we can simply use **Peta** as a **prefix**.

## What Are Prefixes?

A **prefix** is a specific term or word that is used before any sort of quantity to enhance or modify its meaning. **Prefixes** help us to express very large or very small **quantities**. Using **prefixes** makes the quantity easy to read and elaborate.

Instead of using a very large(or small) number of **zeroes**, one can simply add any **prefix** to make the quantity understandable such as one tera representing 1,000,000,000,000 (trillion) and one **pico** representing 0.000,000,000,001 (trillionth).

Hence, we can use **tera** in place of trillion and **pico** in place of trillionth.

**Prefixes** play a broad role in physics and mathematics because both fields deal with measuring quantities, and by using **prefixes**, it becomes easy to represent any unit.

There is a total of 20 SI **prefixes** that are commonly used. Namely,

## What Are SI Units?

**SI unit** is an international system of measurements that are used universally in **scientific** and **technical** research to abstain from confusion and uncertainty. To have a standard system of units, it becomes convenient to understand and recognize the **measurements** in one set of unit systems. **Meter, kilogram, second, and ampere are SI units of length, mass, time, and current.**

SI units are of **two **types:

**Base units** are the **fundamental** units. All the other SI units are derived from these. Therefore base units are also known as the **building** blocks of the system. There are 7 base SI units i.e., meter (m), kilogram (kg), second (s), ampere (A), kelvin (K), mole (mol), and candela (cd).

**Derived units**, as the name **indicates**, are derived from base units. they are infinite in number as they are formed by applying different **techniques** on base units. **Newton** (kg.ms^{-2}), hertz (s^{-1}), coulomb (s.A), and ohm(kg.m^{2}.s^{-3}.A^{-2}) are the units of force, **frequency**, electric **charge**, and **resistance**.

## Using Prefixes With SI Units

Now we discuss how to use **prefixes** with these SI **units**.

First, we talk about length.

some units of measuring length are mega meter (Mm) = 1000^{2} meters, kilometer (km) =1000 meters, millimeter(mm) = 1000^{-1} meters, picometer (pm) = 1000^{-4} meters, Petameter (Pm) = 1000^{5} meters, etc.

some common units to measure weight are **hectogram** (hg)= 1000^{2/3} grams, kilogram (kg) = 1000 grams, decigram (dg) = 1000^{1/3} gram, nanogram (ng) = 1000^{-3} gram, Petagram (Pg) = 1000^{5} gram, etc.

some common units to measure electric current are mega **ampere** (MA) = 1000^{2} ampere, pico ampere (pA) = 1000^{-4} ampere, **Peta** ampere (PA) = 1000^{5} ampere, nano ampere (nA) =1000^{-3} ampere, etc.

In the same manner, we can make use of **prefixes** with different units.

## Metric System

**The Metric** **system** emerged in 1799, during the French revolution. A **Metric** system is a system that is used to measure distance, length, volume, weight, and **temperature**. It is a smaller, more precise, and more effective system to use. This system is based on three units.

Meter (m) â€“ unit of **length**

Kilogram (kg) â€“ unit of **mass**

Second (s) â€“ unit of **time**

These three units can be used to measure almost every **quantity** that is in use today. **The Metric** **system** is easy to understand and operate as compared to the SI system which is a pity-wide system to use.

There are some quantities whose units are based on the kilogram, meter, and second such as area (unit: m^{2}), volume (unit: m^{3}), **density** (unit: kg/m^{3}), speed (unit: m/s), etc.

### Advantages of Using SI Units

- It is a
**coherent**system. - It is a logical and
**well-organized**system. - It is easy to understand.
- It makes
**difficult quantities**easy to comprehend. - SI system is the metric system.
- Easy to convert from one unit to another.
**Prefixes**are the same for all units.- It is the
**whole**system of units. - It has removed the
**communication**gap. - It is based on the
**decimal**system.

### Disadvantages of Using SI Units

It mainly focuses on one unit, so other units are **neglected**.

It cannot always **accurately** define a **quantity**.

## How To Convert Prefixes

Learn the meaning of both the units between which **conversion** is going to be made. Using this knowledge, you can convert between any given prefixes easily.

For example, if you want to convert centi into milli, you must know (a) the value, and (b) what **milli** represents. Now, we know that **centi** represents 10^{-2} and **milli** represents 10^{-3}. To **convert** centimeters into **millimeters**, remember the conversion ratio, i.e., 1 **centimeter** is equal to 10 millimeters.

If we have to convert 20 **centimeters** to millimeters, we multiply 20 by 10, i.e., 20*10 = 200 **millimeters**.

By using these three steps, conversions can be made from one unit to another.

**Convert Peta To Tera**

Consider another example, convert 50 **Peta** to tera.

The first step is to know the values of **Peta** and tera. **Peta** represents 10^{15} and **tera** represents 10^{12}.

The second step is to know the **conversion** ratio, i.e., 1 **Peta** is equal to 1000 tera.

The last step is to perform the required operation. Since we want to convert the larger **prefix** units into the smaller units, so we multiply the number, i.e., 50 **Peta,** by 1000 to get the required result. 50 *1000 = 50000 tera.

**Convert Peta To Giga**

15 **Peta** to Giga:

1 **Peta** = 1000,000 Giga

15 **Peta** =15 * 1,000,000 Giga = 15,000,000 Giga

**Convert Peta To Mega **

0.01 **Peta** to mega:

1 **Peta** = 1,000,000,000 mega

0.01 **Peta** = 0.01 * 1,000,000,000 = 10,000,000 mega

**Convert Peta To Kilo**

75 **Peta** to kilo:

1 **Peta** = 1,000,000,000,000 kilos

75 **Peta** = 75 * 1,000,000,000,000 = 75,000,000,000,000 kilo

## Solved Example

Let us consider an example of a power plant, under normal circumstances, produces 200 PWh. How much energy is that?

### Solution

The symbol PWh stands for **Peta** watt per hour. **P** stands for **Peta** i.e 10^{15}, **Peta** watt per hour means that 200,000,000,000,000,000-watt **electricity** per hour. Suppose that an average light **bulb** consumes 20 watts per hour. If we divide the **power** produced by the power plant by the energy consumed by a light bulb per **hour**, we come to the conclusion that the plant **provides** **energy** enough for 10,000,000,000,000,000 light **bulbs** per hour.

*All images/mathematical drawings were created with GeoGebra.*