Question

When the Sun is directly overhead, a hawk dives toward the ground with a constant velocity of 5 m/s at 60 degrees below the horizontal. Calculate the speed of its shadow on the level ground.

Answer 1

I'm basically making a triangle, and I know (or at least I'm hoping) that the shadow is the horizontal component of the vector that is the hawk's flight. If it's 60 degrees below the "horizontal" or, the way I see it, the "line of sight", the direction is equivalent to 300 degrees if making an imaginary coordinate grid at the point before she descends, making the h.c. = 5.00cos300. Or, actually, the entire thing is a 30-60-90 triangle, so the velocity of her shadow is 2.5 m/s. 

Reference https://www.physicsforums.com/threads/diving-hawks.180141/

Answer 2

The shadow that will be protected on the ground will represent the hawk's horizontal position. therefore it will move at the hawk's horizontal velocity component, which is:
5*cos(60) = 2.5 m/s