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

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

Explanation:

Free fall formula is:

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

1.92 sec.

are their multiple choices ?

explanation:

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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