Convert 17,660 ft/min to mi/hr: Math Error?

[cwalker8184]

Convert 17,660 ft/min to mi/hr, ft= feet, min=minutes, mi=miles, hr=hours
I first divided 17,660 feet per minute by 5280 ft then divided that quantity by 60 minutes and got 0.06 miles per hour. What did I do wrong?

 

[berkeman]

Convert 17,660 ft/min to mi/hr, ft= feet, min=minutes, mi=miles, hr=hours
I first divided 17,660 feet per minute by 5280 ft then divided that quantity by 60 minutes and got 0.06 miles per hour. What did I do wrong?

When doing unit conversions, I find it best to keep multiplying by "1". You did the first part of the conversion correctly:

17,660 ft/min * (1 mile / 5280 ft) = 3.345 mile/min

But in the second part, what form of "1" should you multiply by to get to mile/hr?


EDIT -- Keep in mind that by multplying by "1", your goal is to cancel out like units on the top and bottom of the fraction...

 

[jim hardy]

always write it out before start keying into calculator.