Question

Spring Airlines Flight 123 is currently flying at a height of 45,000 feet and will descend at a rate of 700 feet per minute. At the same time, Summer Airlines Flight 789 is taking off from ground level and will ascend at a rate of 1,200 feet per minute. Which equation can be used to find m, the number of minutes it will take for the two planes to be at the same height?

Answer 1

23.68421052632 minutes

Explanation:

Given that :

Spring airlines :

Current height = 45,000

Rate of descent = 700 ft per minute ; represent descent rate as negative

Summer airlines :

Current position = ground level = 0

Rate of ascent = 1200 ft per minute

Number of minute it will. Take for the 2 planes to be at the same height :

Height * descent rate = height * ascent rate

45000 + (-700)m = 0 + 1200m

45000 - 700m = 0 + 1200m

-700m - 1200m = 0 - 45000

-1900m = - 45000

m = 45000 / 1900

m = 23.68421052632 minutes

Hence the two planes will be at the same height after 23.68421052632 minutes