1. What is an Average Speed Calculator For Two Speeds?

Definition: This calculator computes the harmonic mean of two speeds when equal distances are traveled at each speed.

Purpose: It helps determine the true average speed for trips where different speeds are maintained over equal distances.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( AS \) — Average speed (mph)
• \( V1 \) — First speed (mph)
• \( V2 \) — Second speed (mph)

Explanation: This is the harmonic mean, which properly accounts for the time spent at each speed when distances are equal.

3. Importance of Average Speed Calculation

Details: Correct average speed calculation is crucial for trip planning, fuel efficiency estimates, and travel time calculations.

4. Using the Calculator

Tips: Enter both speeds in mph. The calculator works for any speed unit as long as both inputs use the same unit.

5. Frequently Asked Questions (FAQ)

Q1: Why not just average the two speeds?
A: The arithmetic mean would only be correct if equal time was spent at each speed. For equal distances, the harmonic mean is required.

Q2: Does this work for more than two speeds?
A: No, this formula is specifically for two speeds. For more speeds, a generalized harmonic mean formula would be needed.

Q3: What if one speed is zero?
A: The formula becomes undefined (division by zero) as you can't have an average speed if part of the distance isn't moving.

Q4: Can I use km/h instead of mph?
A: Yes, as long as both speeds use the same units, the result will be in those units.

Q5: When is this calculation most useful?
A: For trips where you know you'll travel equal distances at different speeds, like highway and city driving segments of equal length.