Physics power problem?

baked-potato

http://min.us/ljJoz0xI1zpWS

old-science-guy

well

P = W/t

and W = F d

so

P = (F d)/t

and d/t = v

so

P = F v

and here F = m g where m = 2L*1kg/L = 2kg

then

P = m g v

78w = 2kg * 9.81N/kg * v(m/s)

v = 3.9755 or about 4m/s