Question

Bill kicks a rock off the top of his apartment building. It strikes a window across the street 16 m away. The acceleration of gravity is 9.8 m/s 2 . If the window is 18 m below the position where Bill contacted the rock, how long was it in the air

Answer 1

Answer:

The time that pass when rock in the air is 1.92 secs.

Explanation:

Free fall formula is:

$y(t)=1/2*g*t^2$

The rock free falls from above 18m than the time that pass for this situation:

$18=1/2*9.8*t^2\\t^2=36/9.8\\t=1.92$

1.92 sec.