Jet is flying at 500 mph east relative to the ground. A Cessna is flying at 150 mph 60° north of west relative to the ground. What is the Cessna's speed relative to the 747? A 634 mph B 578 mph C 590 mph D 444 mph E 610 mph

C. 590 mph

Explanation:

Given:

Taking the x-axis alignment towards east and hence we have the velocity vector of the jet as reference.

Refer the attached schematic.

So,

&

Now the vector of relative velocity of Cessna with respect to jet:

Now the magnitude of this velocity:

is the relative velocity of Cessna with respect to the jet.