An archer shoots an arrow with an initial velocity of 21 m/s straight up from his bow. He quickly reloads and shoots another arrow the same way 3 s later. At what time and height do the arrows meet?

1 Answer
Dec 31, 2014

The first arrow and the second meet at a height y.

Explanation:

#t=3.64 s#
#y=11.4 m#

The first arrow and the second meet at a height #y#.

The first one takes a time #(t+3)# to reach this point while the second a time #t#.
We use the relationship of kinematics:
#y=v_it+1/2at^2#
Where #v_i# is the initial velocity and #a# is the acceleration of gravity.
So we have:

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(I rounded a little bit....)