Final answer:
To find the distance between the planes after 3 hours, calculate the distances each plane has traveled and use the Law of Cosines.
Step-by-step explanation:
To find the distance between the planes after 3 hours, we first need to calculate the distances each plane has traveled in 3 hours.
For the first plane:
Distance = Speed × Time = 400 miles/hour × 3 hours = 1200 miles.
For the second plane:
Distance = Speed × Time = 500 miles/hour × 3 hours = 1500 miles.
Now, we can use the Law of Cosines to find the distance between the planes:
d^2 = a^2 + b^2 - 2ab*cos(C)
d^2 = (1200)^2 + (1500)^2 - 2(1200)(1500)*cos(30°)
d^2 = 1440000 + 2250000 - 3600000*(√3/2)
d^2 = 3690000 - 3600000*(√3/2)
d^2 = 3690000 - 1800000*√3
d ≈ √(3690000 - 1800000*√3) ≈ 932.48 miles.