Why were two plugs of potato needed for this cannon?
(One plug sealed the muzzle end of the cylinder. The
projectiles were placed atop of this "load" plug. The
second plug was needed to seal the airtight chamber. This
second plug was pushed into the cylinder and produced
the increased air pressure needed to "pop" the load plug.)
the cannon fire if the plugs did not form an airtight
(No. If the seals were not airtight, then the necessary
pressure would not build within the cannon cylinder.)/li>
did the distance to the target affect the spread of projectiles?
(The further the distance, the greater the circumference
of the scatter pattern.)
does the friction between the "load" plug and the chamber
wall affect the air blast?
(If the friction is increased (i.e. if the dowel is
pushed quickly),then the plug can withstand a greater
pressure. With a greater pressure, the projectiles would
be hurled a further distance. If the friction is reduced,
then the load plug moves with very little pressure. Since
an explosive pressure would not build within the chamber,
the projectiles would slowly be pushed out of the pipe.)
was it important to apply the same amount of pressure
to the dowel during the two tests?
(The diameter of the scatter would also be affected
by the amount of friction, or the amount of pressure applied
to the dowel. To try to eliminate this variable, the dowel
should be pushed at a similar rate.)
Unlike a shotgun or pistol can leave powder burns formed
by the hot gases and materials that escape from the muzzle
of the fired weapon. Explain how these burns might be used
to infer the distance between weapon and victim.
(The nearer the target, the more likely the target will
be peppered with the chemicals that are released during