Posted by Skylar on .
You throw a ball downward from a window at a speed of 2.0m/s. The ball accelerates at 9.8m/s^2. How fast is it moving when it hits the sidewalk 2.5m below?

physics 
Anonymous,
initial speed: 2 m/s
a: 9.8 m/s^2
s: 2.5 m
final speed: ?
Vf^2  Vi^2 = 2as
v^2  2^2 = 2•9.8•2.5
v^24 = 49
v^2 = 53
final speed is approx. 7.28