Question 230569
D=RT
R=D/T
R=1200/4
R=300 MPH. IS THE SPEED WITH THE JET STREAM.
R=560/4
4=140 MPH. IS THE SPEED AGAINST THE WIND.
(300-140)/2=160/2=80 MPH. IS THE SPEED OF THE WIND.
PROOF:
300-80=220 MPH. IS THE SPEED OF THE PLANE IN STILL AIR.
140+80=220 MPH. DITTO.