# Speed, Distance, Time || Speed, Distance & Time formula

## What is Speed?

Speed tells how fast you are covering distance in a particular time.

Given above are the image of two cars.

Speed of Car A = 50 km/hr
It tells that car A travels 50 km distance in 1 hour time

Speed of Car B = 120 km/hr
It means car B travels 120 km distance in 1 hour

Hence, Speed of Car A > Car B as it travels more distance in one hour time

## Formula for Speed

The speed of any object can be calculated using following formula

\mathtt{Speed=\frac{Distance}{Time}} \\\ \\ \mathtt{S\ =\ \frac{D}{T}}

Hence, if you know the distance covered by object at a particular time, you can calculate its speed.

Example 01
A car travels 60 km distance in 3 hours. Find the speed of the car

Given
Distance travelled (D) = 60 Km
Time taken (T) = 3 hours

\mathtt{Speed=\frac{Distance}{Time} \ }\\\ \\ \mathtt{Speed\ =\ \frac{60}{3} \ =\ 20\ km/hr}

Hence, the speed of car is 20 km/hr
It also means that the car travels 20 km in one hour

Example 02
A scooter travels 20 meter in 5 seconds. Find the speed

Given
Distance Travelled (D) = 20 meter
Time taken (T) = 5 seconds

\mathtt{Speed=\frac{Distance}{Time} \ }\\\ \\ \mathtt{Speed\ =\ \frac{20}{5} \ =\ 4\ m/sec}

Hence, the speed of scooter is 4 meter/second
It also means that scooter travels 4 meter every one second

## Unit of Speed

The standard unit of speed is meter/seconds

Other common units for expressing speed are:
⟹ kilometer/hour (km/hr)
⟹ miles/hour (mph)
⟹ meter/second (m/s)

Explanation
The below cyclist covers 27 meter distance in 9 seconds.
Find the speed

We know that;
\mathtt{Speed=\frac{Distance}{Time} \ }\\\ \\ \mathtt{Speed\ =\ \frac{27\ meter}{9\ seconds} \ =\ 3\ m/sec}

Observe how speed is expressed in meter/seconds (m/s) after the formula calculation

### Converting meter/second to kilometer

Some questions specifically ask about speed converted in km/hr.

Below is the shortcut to convert speed from m/s to km/hr

we know that:
1 meter = 0.001 Km

1 hour = 60 x 60 seconds = 3600 seconds

1 second = 1/3600 hour

Converting meter/second into km/hr

\mathtt{\frac{meter}{second} \ =\ \frac{0.001\ km}{\frac{1}{3600} \ hr} \ =\ 3.6\ km/hr}

Conclusion: To convert speed from meter/sec to Km/hr just multiply the speed with 3.6

## How to calculate Distance Travelled

When you know the speed of the object and the time of travel, you can easily calculate the distance using the speed formula mentioned above

We know that:
\mathtt{Speed\ =\ \frac{Distance}{Time}}\\\ \\ \mathtt{Distance\ =\ Speed\ \times \ Time}

## Speed, Distance, Time – Questions

(01) A car travelled at the speed of 30 km/hr for 10 minutes. Find the distance travelled by the car

Given
Speed (S) = 30 km/hr
Time (T) = 10 minutes

Here the speed is given in km/hr, while time is in minutes.

To make data consistent, convert the time into hour

we know that
1 minute = 1/60 Hour

10 minute = 1/6 Hour

Now the time (T) is = 1/6 Hour

Using the formula:
Distance = Speed x Time

Distance = 30 x (1/6) = 5 km

Hence, the distance travelled by car is 5 Km

(02) Distance between city A & city B is 20,000 meter. A car travels from A to B in 45 minutes. Find the speed of the car in km/hr.

Given
Distance = 20,000 meter

we know that;
1 meter = 0.001 Km
20,000 meter = 20,000 x 0.001 = 20 Km

Time taken = 45 minutes

we know that;
1 minute = 1/60 hour
45 minute = 45/60 hour = 3/4 Hour

Hence,
Distance (D) = 20 Km
Time (T)= 3/4 Hour

We know that;
Speed = Distance/Time

\mathtt{Speed\ =\ \frac{20}{\frac{3}{4}}}\\\ \\ \mathtt{Speed\ \ =\ \frac{20\times 4}{3} \ =\frac{80}{3} \ =\ 26.7\ Km/hr}

Hence, the speed of car is 26.7 km/hr

(03) A bird flies at the speed for 3 hours at the speed of 15 km/hr. Find the distance travelled by bird in meter

Solution
Speed (S) = 15 Km/hr

Time (T) = 3 hours

Using the formula;
Distance\ =\ Speed\ \times \ Time\\\ \\ Distance\ =\ 15\ \times \ 3\ =\ 45\ km

We have to calculate distance in meters.

we know that;
1 km = 1000 meter
45 km = 45,000 meter

Hence, 45000 meter is the solution

(04) A spacecraft travels at the speed of 15 km/second. Find the distance travelled in 2 hours.

Speed = 15 km/sec

Convert km/sec into km/hr

We know that;
1 second = (1/3600) hour

\mathtt{\Longrightarrow \ 15\ \ \frac{km\ }{sec} \ }\\\ \\ \mathtt{\Longrightarrow \ 15\ \frac{km}{\frac{hr}{3600}} \ }\\\ \\ \mathtt{\Longrightarrow \ 54000\ \frac{km}{hr} \ }

Hence;
Speed (S) = 54000 km/hr
Time (T) = 2 hr

Using the formula;
Distance = Speed x Time

Distance = 54000 x 2 = 108000 kms

Hence, the space craft will travel 108000kms in 2 hours

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