Answer:
a). 170 miles
b). Planes will be 500 miles apart after 1.1 hours.
Step-by-step explanation:
a). Two planes heading towards North and South when passed each other were 80 miles apart.
Distance between these planes after 20 minutes or hours.
From the figure attached,
In right angle triangle DEC,
DE = 80 miles
BE = (Speed × duration) = miles
Similarly, BC = miles
By Pythagoras theorem,
DC² = EC² + DE²
= (EB + BC)² + DE²
= (100 + 50)² + (80)²
= 28900
DC = √28900 = 170 miles
b). Now we have to evaluate the duration after which distance between the planes is 500 miles.
Let after t hours planes will be 500 miles apart.
Then EB = 300t
BC = 150t
Therefore, EC = EB + BC = 450t
It's given that DC = 500 miles
By Pythagoras theorem again,
DC² = EC²+ DE²
(500)²= (450t)²+ (80)²
250000 = 202500t² + 6400
2500 = 2025t² + 64
2025t² = 2436
t² = 1.20297
t = 1.097 hours ≈ 1.1 hours
Therefore, both the planes will be 500 miles apart after 1.1 hours.
Step-by-step explanation:
