Question

"A hole is punched in a full milk carton, 10 cm below the top. What is the initial velocity of outflow?" This is the only information given.

Answer 1

http://en.wikipedia.org/wiki/Bernoulli%27s_principle this should help.

Answer 2

Bernouli's equation:
\[P_1 + \frac{1}{2}\rho v_1^2 + h_1\rho g = P_2 + \frac{1}{2}\rho v_2^2 + h_2\rho g\]
With P1 = P2 because they are both exposed to the outside atmosphere
v1 approximately = 0
and h2 = 0,
that is easy to solve for v2