Question

A cyclist rides his bike at a speed of 22 feet per second. what is this speed in miles per hour? how many miles will the cyclist travel in 4 hours? in your computations, use the fact that 1 mile is equal to 5280 feet. do not round your answers.

Answer 1

1 second = 22 feet

Find 1 minute:
1 min = 22 x 60 = 1320 feet [1 minute = 60 seconds]

Find 1 hour:
1 hour = 1320 x 60 = 79200 feet [1 hour = 60 minutes]

Find in miles:
1 hour = 79200 ÷ 5280 = 15 miles [1 mile = 5280 feet]

Answer: speed = 15 miles/hour

1hour = 15 miles

4 hours = 15 x 4 = 60 miles

Answer: 60 miles

Answer 2

First we set up proportions to find out how many miles per hour the cyclists rides his bike at.

Let ft = feet, sec = second(s), min = minute(s), hr = hour(s), mi = mile(s)


`(22 ft)/(sec) * (60 sec)/(min) * (60 min)/(hr) * (1 mi)/(5280 ft)`

Translation of all that: The cyclist goes 22 feet per second. There are 60 seconds in a minutes and 60 minutes in an hour. 1 mile is equal to 5280 feet. Multiply these fractions all together; everything will cancel except for miles divided by hours AKA miles per hour.

22 * 60 * 60 * 1 = 79200
79200 / 5280 = 15

He is going 15 miles per hour. So he will go 60 miles in 4 hours.