A pelican dives downward from a height of #35# #m# with an acceleration of #9.8# #m##/s^2# to grab a sardine at the surface of the ocean. How long does the dive take?

1 Answer
May 8, 2018

The dive takes 2.673 seconds.

Explanation:

We'll use the following kinematics equation to solve for time:

#D=V_it+1/2at^2#

If the pelican is traveling at 0 #m//s# vertically at #t=0#, then that means #V_i=0#. Additionally, if you consider the fact that the distance traveled and acceleration is both the same direction, then sign doesn't matter:

#35=(0)xxt+1/2(9.8)t^2#

#35=4.9t^2#

#7.14286=t^2#

#color(green)(t=2.673s)#