How to get 65 miles per hour What is the speed in feet per second?

Answer 1

We have the following ratio:

65 miles / 1 hour

The first step is to convert the hours into seconds. We multiply this ratio by 1 hour over 3600 seconds:

(65 mi.)/(1 hr.) times (1 hr./3600 sec.)

We did this because 1 hour is equal to 3600 seconds, so we're pretty much multiplying by one (which does not affect the original ratio), and making it so that we can cancel out 1 hour (since we're both multiplying and dividing by 1 hour, which is again like multiplying by 1).

65 mi. / 3600 sec.

The next step is converting miles to feet. There are 5280 feet in one mile. We do something similar to the first step:

(65 mi. / 3600 sec.) times (5280 ft. / 1 mi.)

65 mi. is not the same as 1 mi., so we cannot get rid of them so easily. If we multiply by (65/65), which is equal to 1, we can make the second ratio more compatible with the first.

(65 mi. / 3600 sec.) times (5280 ft. / 1 mi.) times (65/65)

(65 mi. / 3600 sec.) times (343200 ft. / 65 mi.)

Now, cancel 65 miles like we did in the first step:

343200 feet / 3600 seconds

There is the answer! The only problem is that there are two big numbers being divided into one another. If we simplify this ratio, it will become more clear. Notice that both the numbers can be divided by 100:

3432 feet / 36 seconds

After dividing 3432 by 36, we get approximately:

95.333 feet per second