Plz help :(
Two planes left simultaneously from the same airport and headed in the same direction towards another airport 3600 km away. The speed of one of the planes was 200 km/hour slower than the speed of the other plane, and so it arrived at its destination 1.5 hours after the faster plane. Find the speeds of both planes.

Respuesta :

Answer:

[tex]v_1=800\ Km/h\\v_2=600 \ Km/h[/tex]

Step-by-step explanation:

Constant Speed Motion

Let's assume the speeds of both planes are v1 and v2 respectively, the plane 2 slower than the plane 1, thus

[tex]v_1-v_2=200[/tex]

Solving for v1

[tex]v_1=200+v_2\ \ \text{ .................[1]}[/tex]

The time the faster plane took to arrive is

[tex]\displaystyle t_1=\frac{x}{v_1}[/tex]

The time the slower plane took to arrive is

[tex]\displaystyle t_2=\frac{x}{v_2}[/tex]

We know that

[tex]t_2-t_1=1.5[/tex]

Or, equivalently

[tex]\displaystyle \displaystyle \frac{x}{v_2}-\frac{x}{v_1}=1.5[/tex]

Using x=3600 and replacing [1]

[tex]\displaystyle \displaystyle \frac{3600}{v_2}-\frac{3600}{v_2+200}=1.5[/tex]

Operating

[tex]3600(v_2+200)-3600v_2=1.5v_2(v_2+200)[/tex]

Operating and simplifying

[tex]v_2^2+200v_2-480000=0[/tex]

Solving for v2:

[tex]v_2=600,\ v_2=-800[/tex]

We take the positive solution

[tex]\boxed{v_2=600 \ Km/h}[/tex]

Thus

[tex]v_1=600+200=800[/tex]

[tex]\boxed{v_1=800\ Km/h}[/tex]