Question

A train travels $700$ meters in $35$ seconds. What is its speed in $km{h^{ - 1}}$ ?

Answer 1

Hint: Use the relation between speed distance and time to find the speed of the train. Convert the units of distance from meters to kilometers and time from seconds to hours to get our required value of speed in kilometres per hour.

Complete answer:
We have been given that the train travels $700$ meters and it is taking time about $35$ seconds
Let's start by converting the provided distance from meters to kilometers.
We know that $1$ meter is equal to $0.001$ kilometers
Therefore, $700$ meter is equal to $0.7$ kilometers
Now converting the provided time from seconds to hours
We know that $1$ hour is equal to $3600$seconds
So, $1\sec = \dfrac{1}{{3600}}hours$
Therefore $35$ seconds is equal to $\dfrac{{35}}{{3600}} = 0.009$ hours
Now in order to find the speed of the train we will be using the relation between speed distance and time, which is given as
$s = \dfrac{d}{t}$
Where, $s$ is the speed of the train, $d$ is the distance covered by the train and $t$ is the time taken by the train.
Putting values of distance and time from above we get
$s = \dfrac{{0.7}}{{0.009}}$
$ \Rightarrow s = 77.77km{h^{ - 1}}$
Hence if a train travels $700$ meters in $35$ seconds its speed in $km{h^{ - 1}}$ is found to be $s = 77.77km{h^{ - 1}}$

Note:
From the relation of speed, distance and time we can see that it indicates how quickly or slowly an object moves. It specifies the distance traveled by the objects and the time taken by the object to complete the journey. In addition, as speed improves, the time required decreases, and vice versa.