Answer:
0 Hz as there is no relative moving between jets so there is no shift in the frequency.
Explanation:
The jet in which the receiver is present and the jet which is emitting the radio waves of frequency 2.0×10⁶ Hz are moving at same speed. Hence, between the two jets, there is no relative motion and thus , for one of the system , the other is at rest. So, there will be no change in frequency as the radio waves receives the receiver with same frequency because there is no frequency shift.