Solving for Time

Date: 2/1/96 at 20:38:36
From: Anonymous
Subject: word problem

You are traveling 55 mph over a bridge that is 4260 ft. long. How 
long does it take to cross the bridge?

Help me!

Date: 6/15/96 at 9:14:59
From: Doctor Robert
Subject: Re: word problem

Remember that distance = (rate)(time).  If you solve this for time 
you get time = (distance)/(rate).  

Your problem involves two different units of distance.  We must 
convert miles to feet.  1 mile = 5280 ft.

The answer to your problem is then 

time = 4260 ft/290400 ft/hr = .01467 hr

You can convert this to minutes by multiplying by 60.  The time 
would be .8801 minutes or approximately 52.8 seconds.

Doctor Robert, The Math Forum