Atrain is approaching a signal tower at a speed of 40m/s. the train engineer sounds the 1000-hz whistle, while a switchman in the tower responds by sounding 1200-hz siren. the air still and the speed is 340m/s. what is the frequency of the train whistle tone that is heard by the switchman? 300/340x1000hz 380/340x1000hz 340/300x1000hz 1000hz 340/380x1000hz

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i. e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i. e. include the distance traveled to the first encounter)