well you flip the switch which says torpedo then woooooosh off it goes

A torpedo is not "shot" from a submarine; it is launched. The torpedo is in the torpedo tube, compressed air is used to launch the torpedo out of the tube at speed; as the torpedo exits the tube its' own propulsion (motors) start and propel the torpedo to the target.

no because torpedos are self propelled, people are too but the are to slow to be "launched" from a torpedo tube.

Torpedo tubes facing the rear (aft) of the vessel.

A torpedo "in the tube" and ready to be launched.

The only thing necessary for it to launch is the launch directive.

About six feet.

Torpedoes aren't like bullets; they have little engines that propel them to their targets. No one wants the engine to start while the torpedo is still in the boat, so the torpedo is shot about six feet out of the tube with a huge burst of compressed air. After it's free of the boat, the engine starts and propels the torpedo as far as it will swim...the Navy's Mk.48 torpedo will go 20 to 30 miles depending on how fast they set it to go.