Final answer:
It would take 0.5 hours, or 30 minutes, for the airplane to travel 400 miles at a speed of 800 miles per hour, using the formula time equals distance divided by speed.
Step-by-step explanation:
To determine how long it will take an airplane traveling at a constant speed to cover a certain distance, we can use the basic formula of time taken (t) which is equal to distance (d) divided by speed (v), t = d/v. Here, the airplane flies at a constant speed of 800 miles per hour, and we want to find out how long it would take to travel 400 miles.
Step 1: Write down the formula for time: t = d/v.
Step 2: Insert the values into the formula: t = 400 miles / 800 miles per hour.
Step 3: Calculate the time: t = 0.5 hours.
So, it would take 0.5 hours, or 30 minutes, for the airplane to travel 400 miles at a constant speed of 800 miles per hour.