Pierre drives to work (a distance of 51 miles) at a speed of 71 mph and returns
ID: 3441179 • Letter: P
Question
Pierre drives to work (a distance of 51 miles) at a speed of 71 mph and returns home at a speed of 56 mph. What is his average speed for the round trip? Use the harmonic mean. Pierre drives to work (a distance of 51 miles) at a speed of 71 mph and returns home at a speed of 56 mph. What is his average speed for the round trip? Use the harmonic mean. Pierre drives to work (a distance of 51 miles) at a speed of 71 mph and returns home at a speed of 56 mph. What is his average speed for the round trip? Use the harmonic mean.Explanation / Answer
To get the average speed, we get the harmonic mean of the two velocities.
Thus,
vave = 2 / (1/71 + 1/56) = 62.61417323 mph or 62 78/127 mph [ANSWER]