Answer:
1546.1 mph
Step-by-step explanation:
Let's take the east direction as positive x-direction and north as positive y-direction.
The components of the initial velocity of the jet are:
vx= 858 mph
vy= 0
while the components of the wind's velocity are
ax= (777)(cos 38)= 612.2 mph
ay= (777)(sin38)= 478.4 mph
So, the components of the new velocity of the jet are:
vx=vx+ax= 858+612.2= 1470.2 mph
vy=vy+ay=0 + 478.4 = 478.4mph
And therefore, the new speed is the magnitude of the new velocity, so:
v= vx2+vy2= (1470.2)+(478.4)= 1546.1 mph