posted by donnie on .
a person standing at the edge of a seaside cliff kicks a stone over the edge with a speed of 18 m/s. the cliff is 52 m above the waters surface. how long does it take for the stone to fall to the water? with what speed does it strike the water.
vi= +18 m/s
* theres an arrow for g pointing down.
The time to fall (t) can be computed using
(1/2) g t^2 = 52 m
The final speed can be calculated by realizing that the kinetic energy increases by M g H. That means that
V^2 increases by 2 g H.
Vfinal^2 = 18^2 + 2*9.8*52