3 ms·
You're averaging over distance, but to calculate the average speed you need to average over time. If you drove the first mile at 30 MPH and the second at 90 MPH
by MichaelDickens 8y ago
You're averaging over distance, but to calculate the average speed you need to average over time. If you drove the first mile at 30 MPH and the second at 90 MPH, you'd spend 120 seconds on the first mile and 40 seconds on the second mile, thus giving an average speed of
(120*30 + 40*90) / (120 + 40) = 45 MPH