Question

A vehicle moves at a pace of 16\[m{{s}^{-1}}\]. What distance will it cover in half an hour? Give your answer in kilometers.

Answer 1

Hint: We know the relation between the speed of a moving object, its time duration and the distance covered by it in that time. We can also convert between different units of distance, speed and time to get a solution according to the requirement.

Complete answer:
We know that the distance travelled by a body is dependent on the speed with which it moves and the time duration of its journey. We can use these relations to find any of the unknown physical quantities among these.
In our present situation a vehicle is subject under consideration. It is said to be moving with a speed of 16\[m{{s}^{-1}}\]. We can assume that the body travels along a straight line. Then, the quantity 16\[m{{s}^{-1}}\] refers to the vehicle can cover a distance of 16m in one second of the trip. In that case, we can easily find the distance travelled by the vehicle in any amount of time.
We are asked to find the distance travelled by the vehicle while travelling at a speed of 16\[m{{s}^{-1}}\] for an hour. We can convert the given speed into the terms of kilometers per hour using the relation as –
\[\begin{align}
  & 1m{{s}^{-1}}=\dfrac{3600}{1000}kmh{{r}^{-1}}=\dfrac{18}{5}kmh{{r}^{-1}} \\
 & \Rightarrow 16m{{s}^{-1}}=16\times \dfrac{18}{5}kmh{{r}^{-1}} \\
 & \Rightarrow 16m{{s}^{-1}}=57.6kmh{{r}^{-1}} \\
\end{align}\]
Now, we can find the distance travelled by the vehicle in one hour at the speed as given above as –
\[\begin{align}
  & \text{Velocity=}\dfrac{\text{Distance}}{\text{time}} \\
 & \Rightarrow v=\dfrac{s}{t} \\
 & \Rightarrow s=vt \\
 & \Rightarrow s=57.6kmh{{r}^{-1}}\times 1hr \\
 & \therefore s=57.6km \\
\end{align}\]
The distance travelled by the vehicle in one hour is 57.6km.
This is the required solution.

Note:
The distance covered by the vehicle in a usual situation is using the time taken and the average speed with which it could have travelled. The speed will not be constant in practical cases for an entire trip as there will change in directions and decelerations.