Question

An observer 70 meters south of a railroad crossing watches an eastbound train traveling at 60 meters per second. At how many meters per second is the train moving away from the observer 4 seconds after it passes through the intersection?

(A) 57.60
(B) 57.88
(C) 59.20
(D) 60.00
(E) 67.40

Answer 1

The train is moving away from the observer at a speed of 60 meters per second.

Step-by-step explanation:

To determine the speed at which the train is moving away from the observer, we need to find the distance it has traveled away in 4 seconds. Since the train is moving directly east, its motion does not affect its distance from the observer, which remains constant.

Using the equation distance = speed x time, we can calculate the distance traveled by the train in 4 seconds as follows: distance = speed x time = 60 m/s x 4 s = 240 meters.

Therefore, the train is moving away from the observer at a speed of 240 meters in 4 seconds, which is equivalent to 60 meters per second. Therefore, the correct answer is (D) 60.00.