Answer:
Explanation:
Given
Initial speed is u=V
Maximum height of Pebble is H
Deriving maximum height of Pebble and considering motion in vertical direction

where v=final velocity
u=initial velocity
a=acceleration
s=Displacement
Final velocity will be zero at maximum height


i.e. maximum height is dependent on square of initial velocity
for twice the height

on comparing
Answer:
Explanation:
Check the attachment for solution