(2-6) We can see that the distance travelled by the fish from where Nefertiti releases it to its impact on you is y and let’s say that time t passes while the fish is in motion. Meanwhile, during this same time t, Cormorant will have flown a distance x in the perpendicular direction.
① What is the velocity of the sardine, in Nefertiti’s frame of reference?
② Now let’s switch to Cormorant’s frame of reference (focus on the second part of the diagram). See if you can work out the velocity of the sardine in Cormorant’s frame of reference. If you are not sure, Pythagoras is over there, stroking his beard wisely. He can help.