申論題

2. (12 分) A police cruiser (警車), approaching a right-angled intersection from the north, is chasing a speeding car that has turned the corner and is now moving straight east. When the cruiser is 0.6 km north of the intersection and the car is 0.8 km to the east, the police determine with radar that the distance between them and the car is increasing at 28 km/hour. If the cruiser is moving at 60 km/hour at the instant of measurement, what is the speed of the car? (See Figure 1)