Question

a student is riding his bicycle the 4 km to school from his house. the graph summarizes part of his trip over time. if the student continues riding his bicycle at the same velocity, how much time will it take for him to reach school? 12 minutes 15 minutes 20 minutes 25 minutes

Explanation:

Step1: Calculate the velocity

From the graph, in 10 minutes, the student travels 2 km. Velocity $v=\frac{d}{t}$, so $v = \frac{2}{10}=0.2$ km/min.

Step2: Calculate remaining distance

The total distance to school is 4 km and the student has already traveled 2 km. So the remaining distance $d_{r}=4 - 2=2$ km.

Step3: Calculate remaining time

Using the formula $t=\frac{d}{v}$, with $d = d_{r}=2$ km and $v = 0.2$ km/min. Then $t=\frac{2}{0.2}=10$ minutes. But this is wrong as we mis - read the options. Let's start over.

From the graph, the student travels 2 km in 10 minutes.
The total distance is 4 km.
The time taken to cover 4 km at a constant speed:
Since speed $s=\frac{2}{10}=0.2$ km/min.
For a 4 - km journey, $t=\frac{4}{0.2}=20$ minutes.

Answer:

20 minutes