An airplane travels 720 in 3 hours with the wind. The return trip against the wind takes 4 hours. What is the wind speed and the speed of the airplane in still air?

Wind speed = 30 per hour, Airplane speed = 210 per hour.

Step-by-step explanation:

Given:

An airplane travels 720 in 3 hours with the wind.

The return trip against the wind takes 4 hours.

Question asked:

What is the wind speed and the speed of the airplane in still air ?

Solution:

First of all we will find speed of airplane with the wind:-

Now, let speed of plane =

And let speed of wind =

Speed of of airplane with the wind will be:-

Similarly, we will find speed of airplane against the wind:-

Speed of airplane against the wind will be:-

Adding equation 1 and 2:-

Speed of plane = = 210 per hour.

Speed of wind = = ?

Taking from equation 1:-

Speed of wind = 30 per hour.

Therefore, the wind speed is 30 per hour and speed of the airplane in still air is 210 per hour.

justin bieber ml.

u = -(6/7)w

step-by-step explanation:

place all values with 'u' on one side of the equation.

4u + 8w = - 3u + 2w

4u + 3u = 2w - 8w

further simplify the equation by solving the addition and subtraction.

7u = - 6w

make 'u' the independent variable by placing its co-efficient on the right-hand side.

u = - (6/7)w