$\bf \stackrel{distance}{d}=\stackrel{rate}{r}\cdot \stackrel{time}{t}\quad 
\begin{cases}
d=700\\
t=5
\end{cases}\implies 700=5r\implies \cfrac{700}{5}=r
\\\\\\
\stackrel{mph}{140}=r$

6 0

3 years ago

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Flying against the wind, an airplane travels 7520 kilometers in 8 hours. Flying with the wind, the same plane travels 6500 kilom

bezimeni [28]

Answer:

Rate of plane in still air = 1120 km/h

Rate of wind = 180 km/h

Step-by-step explanation:

Let the rate (speed) of the plane in still air = u km/h

Let the rate (speed) of the wind = v km/h

Formula for speed is:

$Speed = \dfrac{Distance}{Time}$

Given that against the wind, airplane travels 7520 km in 8 hours.

The speed against the wind will be slower so,

Against the wind, speed = (u -v ) km/h

Using above formula:

$(u-v) = \dfrac{7520}{8} km/h\\(u-v) = 940 km/h ..... (1)$

Given that with the wind, airplane travels 6500 km in 5 hours.

The speed with the wind will be faster so,

With the wind, speed = (u +v ) km/h

Using above formula:

$(u+v) = \dfrac{6520}{5} km/h\\(u+v) = 1300 km/h ..... (2)$

Adding (1) and (2) to solve for u and v:

$2u = 2240\\\Rightarrow u = 1120\ km/h$

Putting u in (1):

$1120-u=940\\\Rightarrow u = 180\ km/h$

So, the answers are:

Rate of plane in still air = 1120 km/h

Rate of wind = 180 km/h

6 0

3 years ago