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Two planes take off from John F. Kennedy International Airport, New York, and land at Heathrow, London.

The average speed of the first plane is 495 mph and the flight takes 7 hours.
The average speed of the second plane is 385
mph. How long is the flight from New York to London by the second plane?

User Munleashed
by
7.5k points

1 Answer

4 votes

Answer:

9 hours

Explanation:

The two planes fly thew same distance. Let d = distance.

The first plane flies at speed s₁=495 mph for t₁=7 hours.

The second plane flies at speed s₂=385 mph for t₂=9 hours.

Plane 1:

distance = d

speed = s₁ = 495 mph

time = t₁ = 7 hours

speed = distance/time

distance = speed × time

d = s₁ × t₁

d = 495 mph × 7 hours

d = 3465 miles

The distance is equal for both planes.

The speed and time and different for both planes.

Plane 2:

distance = d = 3465 miles

speed = s₂ = 385 mph

time = t₂ = ?

d = s₂ × t₂

s₂ × t₂ = d

t₂ = d/s₂

t₂ = 3465/385

t₂ = 9

Answer: 9 hours

User Athanassis
by
9.4k points