Answer:
The speed of the wind is 70.7 units.
Explanation:
The velocity of the wind is equal to plane's velocity before the wind minus its velocity after the wind:
[tex]\vec{v_{w}}=\vec{v_1}-\vec{v_2}= (400,100)- (350,50)[/tex]
[tex]\boxed{\vec{v_{w}} = (50,50)}[/tex]
Now, the speed of the wind is the magnitude of [tex]\vec{v_{w}}[/tex]:
[tex]|\vec{v_{w}}| = \sqrt{50^2+50^2}[/tex]
[tex]\boxed{|\vec{v_{w}}| = 70.7}[/tex]
which is the speed of the wind.
P.S: No units are given for speed because no units were provided in the question.