a model airplane flies 18 feet in 2 seconds. What is the airplane's speed in miles per hour?

long ago I memorized a conversion factor:

60mph=88fps

18/88=x/60 will do it.

oops...

9/88=x/60 will do it.

When I was a kid, my dad was appalled that I didn't know that 5,280 feet = 1 mile. Since we were on a long car trip, I had plenty of time to memorize that number. I still remember it after 60 years. <g>

To find the airplane's speed in miles per hour, we need to convert the distance traveled from feet to miles and the time taken from seconds to hours.

Let's start with the distance conversion:
1 mile = 5280 feet

To convert 18 feet to miles, we'll divide by 5280:
18 feet / 5280 feet/mile = 0.003409 miles

Now let's convert the time:
1 hour = 3600 seconds

To convert 2 seconds to hours, we'll divide by 3600:
2 seconds / 3600 seconds/hour ≈ 0.000556 hours

Now we have the distance in miles (0.003409 miles) and the time in hours (0.000556 hours).

To find the speed, we'll use the formula:
Speed (miles per hour) = Distance (miles) / Time (hours)

Speed (miles per hour) = 0.003409 miles / 0.000556 hours ≈ 6133.87 miles per hour

Therefore, the airplane's speed is approximately 6133.87 miles per hour.

It travels 9 feet per second.

9 * 60 * 60 = 32,400 feet per hour

To find the miles per hour, divide:

32,400 / 5,280 = ? miles per hour