Two cars are moving on mutually perpendicular roads towards each other, the speed of the first car is 20 m / s

Two cars are moving on mutually perpendicular roads towards each other, the speed of the first car is 20 m / s, the speed of the second car is 30 m / s. Calculate the V12 of the first car in the frame of reference associated with the second.

The speed of one car relative to another is equal to the difference in the vectors of their speeds. And since the vectors of their speeds are perpendicular to each other (cars are driving on mutually perpendicular roads), the relative speed is calculated by the Pythagorean theorem (since the relative speed will be a vector located on the hypotenuse):

v = √ (v1² + v2²) = √ (30² + 20²) = √1300 = 36.05 m / s.

Answer: v = 36.05 m / s.