Question

The length of the tunnel is 20 meters. A bicycle enters the tunnel at a speed of 3 m/s and leaves the tunnel at 2 m/s. How long did it take for the bicycle to go through the tunnel?

A) 10 seconds
B) 15 seconds
C) 20 seconds
D) 25 seconds

Answer 1

The bicycle took 8 seconds to travel through the 20-meter tunnel, at an average speed of 2.5 m/s.

Step-by-step explanation:

To calculate the time it takes for the bicycle to go through the tunnel, we need to know the average speed of the bicycle. Since the bicycle enters at 3 m/s and leaves at 2 m/s, we can assume a uniform deceleration and find the average of these two speeds. The average speed is calculated as (3 m/s + 2 m/s) / 2 = 2.5 m/s. Now we apply the formula time = distance / speed to find the time it takes to go through the 20-meter tunnel. The distance is 20 meters, and the average speed is 2.5 m/s. So the time is 20 meters / 2.5 m/s = 8 seconds.