PASCO SE-8685 Pulley Demonstration System - Manual (Page 9)

®
Pulley Demonstration System
9
a) Measure the Pulley Force with the Newton Spring Scale
Attach Newton spring scales to
the string on each pulley and
quantitatively discover that the
force exerted for the double
pulley decreases by a factor of
2, while the amount of string
that is pulled increases by the
same factor. Prove that the
number of pulleys relates to
this factor. Show students that
increasing the number of
pulleys increases the mechani-
cal advantage. Discuss the fact
that the amount of work done
is the same in either pulley.
b) Measure the Pulley Force with a Force Sensor and a Computer Interface
Instead of Newton Spring Scales, use two PASCO Force Sensors
to observe real-time force changes in DataStudio software.
1. Connect each Force Sensor to a computer interface (ScienceWorkshop or
PASPORT).
2. Hang one Force Sensor from the single
pulley and the other Force Sensor from the
double pulley. (To hang, screw a hook to the
top of the Force Sensor and tie the hanging
string through the hook.)
3. In DataStudio, open a graph display and
click the Start button to collect data. As you
pull down on each pulley, force data for
both pulleys will appear in the display.
Figure 1.2: Measuring the force
with spring scales
spring scale
Figure 1.3: Connecting the Force Sensor to a PASPORT
interface and to a computer
Figure 1.4:
Pulling on
the Force
Sensor