The tail of a 1-mile long train exits a tunnel exactly 3 minutes after the front of the train entered the tunnel. If the train is moving 60 miles per hour, how many miles long is the tunnel?
The tail (caboose as they used to have) starts 1 mile from the mouth of the tunnel....ti must travel THAT mile PLUS the length of the tunnel in 3 minutes
t = tunnel length
t + 1 = distance the caboose must travel in 3 minutes 3 minutes = 1/20 hr
(t+1) mile / 60 m/hr = 1/20 hr
t + 1 = 60/20
t = 2 miles long
The tail (caboose as they used to have) starts 1 mile from the mouth of the tunnel....ti must travel THAT mile PLUS the length of the tunnel in 3 minutes
t = tunnel length
t + 1 = distance the caboose must travel in 3 minutes 3 minutes = 1/20 hr
(t+1) mile / 60 m/hr = 1/20 hr
t + 1 = 60/20
t = 2 miles long