#  Neglecting air resistance, all objects fall at a rate of 9.8 m/s 2 due to gravity  Because objects fall in a downward direction, we’ll call their acceleration.

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 Neglecting air resistance, all objects fall at a rate of 9.8 m/s 2 due to gravity  Because objects fall in a downward direction, we’ll call their acceleration -9.8 m/s 2  g = acceleration due to gravity = -9.8 m/s 2  Each second that an object falls, it’s speed increases by 9.8 m/s

 The instant an object begins to fall, we will assume it’s v o to be 0 m/s  We will assume maximum speed is just before the object hits the ground

 A brick is dropped from a high scaffold. What is the brick’s velocity after 4 seconds? How far does the brick fall during this time?

 t = 4 seconds  v = ?  d = ?  Anything else?? (anything we should know?)

 Something is being dropped, so we can assume what?  What do we know about acceleration?  Starting distance or time?

 a = -9.8 m/s2  v o = 0 m/s  d o = 0 m

 v = ?  v o = 0 m/s  a = -9.8 m/s 2  t = 4 sec

-39.2 m/s why negative?

 Choose a formula…

 Plug in and solve

-78.4 m  Why negative??

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