### Theory:

In this exercise, we will learn about speed and its various types.

Speed simply tells us how fast an object can move.

Speed is the scalar quantity, which only tells the magnitude (numerical value) of how much speed an object travels.

Speed simply tells us how fast an object can move.

Speed is the scalar quantity, which only tells the magnitude (numerical value) of how much speed an object travels.

**Speed:**

Speed is the rate of change of distance.

$\mathit{Speed}=\frac{\mathit{Distance}\phantom{\rule{0.147em}{0ex}}(d)}{\mathit{Time}\phantom{\rule{0.147em}{0ex}}(t)}$

The SI unit of speed is $\frac{\mathit{meter}\phantom{\rule{0.147em}{0ex}}(m)}{\mathit{second}\phantom{\rule{0.147em}{0ex}}(s)}=\frac{m}{s}=m{s}^{-1}$

And, if we want to calculate the distance using speed and time, we can use the following formula,

$\mathit{Distance}\phantom{\rule{0.147em}{0ex}}=\mathit{Speed}\times \mathit{Time}$.

We can classify the speed into two types with respect to distance and time.

Two types of speed:

**Uniform speed****Non-uniform speed**

**Uniform speed:**

If an object in motion covers equal distances in equal intervals of time, then the object is said to be at a uniform speed.

**Non-uniform speed:**

If an object covers unequal distances in equal intervals of time, the object is said to be in non-uniform speed.

**Average speed:**

We can calculate the average speed of an object by dividing the total distance travelled by the object and the total time taken to travel the distance.

That is, $\mathit{Average}\phantom{\rule{0.147em}{0ex}}\mathit{speed}=\frac{\mathit{The}\phantom{\rule{0.147em}{0ex}}\mathit{total}\mathit{distance}\mathit{travelled}}{\mathit{The}\phantom{\rule{0.147em}{0ex}}\mathit{total}\mathit{time}\mathit{taken}\mathit{to}\mathit{travel}\mathit{the}\mathit{distance}}$

Please note that the unit for average speed is given in \(metre\) \(per\) \(second\) or \(kilometre\) \(per\) \(hour\).

Keep in mind the average speed formula. The unit of average speed is \(metre/second\) when the distance is measured in \(metres\), and the time is measured in \(seconds\).

The average speed unit is \(kilometre\) per \(hour\) when the distance is measured in \(kilometre\), and the time is measured in \(hours\).

We use units like \(centimetres\) per \(second\) in some instances.

SI units are commonly used in science. The \(metre\) is the SI unit of length, and the \(second\) is the SI unit of time. As a result, the SI unit for average speed is the \(metre\) per \(second\).

**Interesting fact:**

The cheetah is the fastest animal on the land, capable of running at \(112\) \(km/h\).

Reference:

https://drive.google.com/file/d/1AYGdDUST3r1rft3AN__yOxqpUMz84qP5/view