A 5.00 kg ball is
dropped from the top of the Systel Building in downtown
Fayetteville. How long does it take the ball to hit the sidewalk if the
building is 45.0 m tall?
A.
2.14 seconds
C.
4.29 seconds
B.
3.03 seconds
D.
9.18 seconds
Down
is positive
a and x are positive.
vo is 0 because it is dropped instead of thrown.
X = vot + 1/2 g t2
= 1/2 g t2
2X
2 x 45.0 m
t = ( ------- ) 1/2 = ( -------------- ) 1/2
= 3.03 seconds
g
9.80 m/s2
