... rates, then the average rate will NEVER be the average of the two rates given for the two legs of the journey In fact, because the object spends more time traveling at the slower rate, the average ... a stopwatch at the start of the trip, what would the stopwatch read at the end of the trip? This is not what a clock on the wall would read, but if you take the difference of the start and end ... hour, then the distance between them is shrinking at a rate of 70 miles per hour If the cars are driving away from each other, then the distance grows at a rate of (a + b) miles per hour Either...