Question

A penny falls from a windowsill which is 25.0 m above the sidewalk. How much time does a passerby on the sidewalk below have to move out of the way before the penny hits the ground?

Answer 1

\[v^2=v_{0}^2+2a \Delta y\] and solve for v then put that v into \[v=v_{0}+at\] and solve for t. i think this will work.