Question

Salma takes 15 minutes from her house to reach her school on a bicycle. If the bicycle has a speed of $2m/s$. Calculate the distance between her house and the school.

Answer 1

Hint
The speed of an object can be defined as the rate of change of distance, which is given by distance divided by time taken to cover the distance. We have to use the same system of units for all variables during calculations.

Formula used: In the solution we will be using the following formula,
$\Rightarrow v = \dfrac{d}{t}$ where $v$ is the speed of the object, $d$ is the distance covered and $t$ is the time taken to cover that distance.

Complete step by step answer
When an object covers equal distances in equal time intervals, the object is said to be moving at a constant speed, and sometimes it is called uniform speed.
To answer the question, we must first consider the formula for speed which is given as
$\Rightarrow v = \dfrac{d}{t}$.
According to the question, the distance is unknown. Thus we must calculate the distance from the given values of its speed and time taken to cover the unknown distance.
Making distance $d$ subject of the formula from the above equation, by multiplying both sides by $t$, we have
$\Rightarrow d = vt$
Usually, we should proceed to insert known values into the equation. However, before that, we must ensure the values of all variables are given in the same system of unit.
From the question we have $v = 2m/s$ but $t = 15\min$, which isn't in the same units. Hence, we must convert the time into seconds.
Since $1\min = 60\operatorname{s}$, then $15\min = 15 \times 60\operatorname{s} = 900s$
Then distance $d$ is given by
$\Rightarrow d = 2 \times 900 = 1800m$
Hence the distance is $d = 1800m$.

Note
In real life scenarios, this time of motion is practically impossible. This is because acceleration from rest and any other undulation in the speed has been neglected in the question. Practically, a person must accelerate from rest to reach a particular velocity, and it is extremely difficult for a person to maintain a constant speed for an entire journey.