A sharp edged orifice with a 50 mm diameter opening in the vertical side of a large tank discharges under a head of 5m. If the coefficient of contraction is 0.62 and the coefficientof velocity is 0.98, what is thedischarge?

Can anybody me with this? ? (picture included.)

Iron is a transition metal with multiple oxidation numbers. (answer the following) a. what is the iron (ii) ion? how does it differ from the iron (iii) ion? b. if iron were to bond with oxygen, predict the formula for each oxidation number of iron. c. how would each formula be named?

Is there a point between a 10 nc charge and a 20 nc charge at which the electric field is zero?