From consecutive aerialphotos of traffic along a highway, one observes that there are ten cars per kilometer with 0 velocity (they are parked), forty cars per kilometer traveling at 15 km/hr and twenty cars per kilometer traveling at 30 km/hr. a) If one were to measure these speeds at a stationary point on the highway, determine the values that would be measured for i) time mean speed, and ii) the mean speed that relates flow to density. Compare these with the value of space mean speed over the highway and comment on the difference.
b) Under what condition(s) are measured values of time mean speed and space mean speed equal