how high does a stone rise if it is initially thrown at a rate of 15m/sec

4 answers

how high should a 2kg mass be lifted the ground at a speed of 15m/sec (g=10m/sec^2)
m g h = (1/2) m v^2

10 h = .5 * 15^2

h = .05 * 225 = 11.25 meters
first question:

PE gained= KE lost
mgh=1/2 m v^2
h= 1/2 v^2/g

second question: makes no sense to me.
Physics