if a plane is flying 235 km/h and encounters west wind at 80 km/hr. What's its new velocity?
That depends upon the direction of its initial velocity. You must have left some words and a number out of your question.
Whatever it is, add the two vectors.
The original velocity is not known because the flight direction has not been given.
For example, if it was heading west, the velocity is simply reduced by 80 k/hr to become 153 k/h (ground speed) heading west.
To determine the plane's new velocity, we need to consider the effect of the wind.
When the plane is flying in still air, its velocity is 235 km/h to the east.
However, since there is a west wind, we need to subtract the wind velocity from the plane's velocity to account for the opposing force.
Therefore, the new velocity of the plane can be calculated by subtracting the wind velocity from the plane's velocity:
New velocity = Plane's velocity - Wind velocity
Substituting the given values:
New velocity = 235 km/hr - 80 km/hr
Performing the subtraction:
New velocity = 155 km/hr
Hence, the new velocity of the plane, when encountering a west wind at 80 km/hr, will be 155 km/hr to the east.