Sure, let's solve this problem step-by-step.
Step 1: Calculate the distance travelled at each speed.
1. For the first part of the journey:
- Speed = 6 km/h
- Time = 2 hours
- Distance = Speed × Time
[tex]\[
\text{Distance}_1 = 6 \text{ km/h} \times 2 \text{ h} = 12 \text{ km}
\][/tex]
2. For the second part of the journey:
- Speed = 4 km/h
- Time = 3 hours
- Distance = Speed × Time
[tex]\[
\text{Distance}_2 = 4 \text{ km/h} \times 3 \text{ h} = 12 \text{ km}
\][/tex]
Step 2: Calculate the total distance travelled.
[tex]\[
\text{Total Distance} = \text{Distance}_1 + \text{Distance}_2 = 12 \text{ km} + 12 \text{ km} = 24 \text{ km}
\][/tex]
Step 3: Calculate the total time of travel.
[tex]\[
\text{Total Time} = \text{Time}_1 + \text{Time}_2 = 2 \text{ h} + 3 \text{ h} = 5 \text{ h}
\][/tex]
Step 4: Calculate the average speed.
The average speed is defined as the total distance travelled divided by the total time taken.
[tex]\[
\text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} = \frac{24 \text{ km}}{5 \text{ h}} = 4.8 \text{ km/h}
\][/tex]
Summary
- The total distance moved by the girl is 24 km.
- The average speed of the girl is 4.8 km/h.
