Thermodynamics >
Heat and the First Law > Heat Capacity
DCS# 4B10.70
RUCHARDT'S
APPARATUS
APPARATUS
10.4 L flask with glass tube
214-02-E
stopwatch
101-05-D4
steel ball
214-02-E
chamois
214-02-E
alcohol
202-02-A
magnet
214-02-E
level
101-05-D4
DESCRIPTION
The ball just barely fits
inside the precision bored glass tube and, when dropped into
the tube, will oscillate on a cushion of trapped air.
The period of oscillation of the ball can be used to determine
the ratio of specific heats, cp/cv, of
the air inside.
NOTES
cp/cv =
4 π2mV/(A2PT2
)
where m = mass of ball
volume of air, V = 10.4 l
cross sectional area of tube,
A = 2.0x10-4 m2
P = atmospheric pressure
Use the chamois and alcohol to
clean the inside of glass tube and the steel ball before
use.
Use a level to make sure that the tube is vertical.
There is a rubber mat inside flask
to protect it when the ball drops. Use the magnet to
retrieve the ball or remove the stopper from the bottom of the
flask.
