Question

9. During a test flight, an aircraft flies from Sandy
Land to White City and back to Sandy Land.
The distance between Sandy Land and White City
is 450 km and the total time taken for the whole
journey is 5 hours and 30 minutes. Given that
there is a constant wind blowing from Sandy Land
to White City and that the speed of the aircraft
in still air is 165 km/h, find the speed of the wind.
State the assumptions you have made to solve
this problem.
Hint: Let the speed of the wind be x km/h.

Answer 1

Answer:

plane speed = 165 km/h

wind speed = x km/h

against wind = 165 - x

with wind = 165 + x

Total distance =450 km Total Time= 5.50 hours

Time upstream + time downstream = 5.5 hours

450 /( 165 - x )+ 450 /( 165 + x )= 5.5

450 ( 165 + x )+ 450 ( 165 - x )= 5.5

74250 + 450 x + 74250 -450 x = 5.5 ( 15^2-x^2)

148500 = 5.5 ( 27225 - x^2 )

148500 = 149737.5 -5.5 X^2

X ^2 = 1237.5

X^2= 225

x= 15 km/h wind speed

Answer 2

Answer:

Solution

Step-by-step explanation:

The distance is 450 km between the two cities. If the speed of the wind is x kph, then, assuming the wind is constant:

450/165+x + 450/165-x=5.5 (5-1/2 hours)

450(165-x)+450(165+x)=5.5(27225-x�)

Solve for x