Acceleration due to Gravity A special case study of uniform acceleration.

Acceleration due to Gravity  Often referred to as free fall  Assumes no air resistance  Symbol: g (9.8 m/s 2 )  Constant vertical acceleration  By convention, upward motion: -g  By convention, downward motion: g

Sample #1 JJJJason hits a volleyball so that it moves with an initial velocity of 6.0 m/s straight upward. If the volleyball starts from 2.0 m above the floor, how long will it be in the air before it strikes the floor? Assume that Jason is the last player to touch the ball before it hits the floor. 1111.50 s VVVVf2=Vi2 + 2asVf=Vi + at

Sample #2  Calculate the displacement and velocity of the volleyball 0.50 s after Jason hits it.  1.8m, 1.1m/s

Sample #3  Stephanie serves the volleyball from a height of 0.80 m and gives it an initial velocity of 7.6 m/s straight up. How high will it go? How long will it take the ball to reach its maximum height?  3.7 m, 0.77 s

Sample #4  A tennis ball is thrown vertically upward with an initial velocity of 8.0 m/s. What will its speed be when it returns to its starting point? How long will it take for it to reach its starting point?  8.0 m/s, 1.63 m

Sample #5  A flowerpot falls from a windowsill 25.0 m above the sidewalk. How fast is the flowerpot moving when it strikes the ground? How much time does a passerby on the sidewalk below have to move out of the way before the flowerpot hits the ground?  22.1 m/s, 2.25 s