Question

You throw a rock straight up into the air with a speed of 14.2 m/s. How long does it take the rock to reach its highest point?
A. 1.4 s
B. 1.2 s
C. 0.7 s
D. 2.1 s

Answer 1

Hi!
the answer is A. 1.4 s
you can found that setting the velocity to be 0 in the equation:
\[v=14.2-9,8t=0\]
since the rock will stop for an instant when it reaches the highest point
:)

Answer 2

thanks greg_D