In the equation the initial velocity given to the explosive is v, and g is the downward acceleration of gravity. So the first thing to note is that the criminal must be higher than Clark’s house and the explosive must be projected vertically (up or down), or just dropped.
The scenario could be:
Lex Luthor made a kryptonite bomb and hired a criminal to drop the bomb on to Clark Kent’s residence in Metropolis. So, late one night, while Superman is asleep, the criminal is in a helicopter hovering 300m directly above Clark Kent’s house. To give himself time to get away, the criminal knows he has to project the bomb into the air before it falls on to the house to destroy Superman. If he has only 10 seconds to get clear, what minimum speed does he have to project the bomb into the air to avoid being caught in the explosion? Assume the acceleration of gravity is 9.8m/s².