An arrow is shot straight up in the air at an initial speed of 15.0 m/s. after how much time is the arrow moving downward at a speed of 8.00 m/s?

t = 2.34 s

Explanation:

As we know that

initial velocity is 15 m/s upwards

final velocity is 8 m/s downwards

acceleration is due to gravity which is given as g = 9.8 m/s/s in downwards direction

now we can find the time to change the velocity using equation of kinematics

here we need to plug in all data

so it will take t = 2.34 s

answer: its c lololo