A mortar shell is to be fired from level ground so as to clear a flat topped building of height h and width a. The mortar gun can be placed anywhere on the ground and can have any angle of elevation. What is the least projection speed that will allow the shell to clear the building? [Hint How is the reqired minimum projection speed changed if the mortar is raised to rooftop level?] = For the special case in which h a, find the optimum position for the mortar and the optimum elevation angle to clear the building.

A mortar shell is to be fired from level ground so as to clear a flat topped building of height h and width a. The mortar gun can be placed anywhere on the ground and can have any angle of elevation. What is the least projection speed that will allow the shell to clear the building? [Hint How is the reqired minimum projection speed changed if the mortar is raised to rooftop level?] = For the special case in which h a, find the optimum position for the mortar and the optimum elevation angle to clear the building.