Question

average speed round trip

Answer 1

To calculate the average speed of a round trip, you can use the formula for average speed:

\[
\text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}}
\]

Here's a step-by-step guide to find the average speed for a round trip:

1. **Determine the Distance:** Identify the distance from the starting point to the destination (let's call it \(d\)). The total distance for a round trip would be \(2d\) (going to the destination and returning).

2. **Determine the Time Taken:** Identify the time taken to go to the destination (let's call it \(t_1\)) and the time taken to return (let's call it \(t_2\)). The total time for the round trip would be \(t_1 + t_2\).

3. **Calculate Average Speed:**
\[
\text{Average Speed} = \frac{2d}{t_1 + t_2}
\]

### Example
- **Distance to Destination:** 100 km
- **Time to Destination:** 1 hour 30 minutes (1.5 hours)
- **Time Back:** 1 hour 15 minutes (1.25 hours)

1. **Total Distance:**
\[
2d = 2 \times 100 \text{ km} = 200 \text{ km}
\]

2. **Total Time:**
\[
t_1 + t_2 = 1.5 \text{ hours} + 1.25 \text{ hours} = 2.75 \text{ hours}
\]

3. **Average Speed:**
\[
\text{Average Speed} = \frac{200 \text{ km}}{2.75 \text{ hours}} \approx 72.73 \text{ km/h}
\]

So the average speed for the round trip in this example would be approximately 72.73 km/h.