Sample problem
lect one of the hydraulic systems from your experiments recorded on the previous page, in which
me syringes were different sizes. your task in this problem is to figure out how much harder it is to
push the piston in the large syringe than in the small syringe.
because the two syringes are part of the same hydraulic system, the pressure exerted on both
pistons is the same. so if you use a subscript to indicate the large piston and the small piston, the
equation above implies that:
flarge
small
p=
i large
small
alarge
large =
alarge
asmall
it's also true that:
small
small
in other words, the ratio of forces on two pistons is the same as the ratio of the areas of the two
pistons. suppose, for example, that you had to exert a force of 5 pounds on the small piston.
determine the area of the ends of the pistons and find out how much more force you need to exert
on a connected large piston to get the water to move back. answer below.