(1)vy*2=2gh
vy=2m/s
V0 = 4m/s
d/V0 =h/vy
h=0.25m
(2)qE=2mg
qEd+mgh=Ek-Ek0
Ek0=m(v0*2+vy*2)/2
Ek=0.225j