Mechanics > Newton's Laws > Newton's Second Law DCS# 1G10.10
TENSION

APPARATUS
cart
 101-05-G1
track
 113B
force sensor or wireless dynamic sensor system (202-13-E5)
 101-05-B2
adapter for force sensor
 107-02-B2
rod with square cross-section
 101-05-B1
two pulleys on clamps
 101-05-G3
200 g mass
 101-05-C
string
 202-02-C3
tall ringstand on table clamp
 202-03-C
LabPro interface
 107-02-B3
laptop with LoggerPro
 206
landing pad
 202-01-A

DESCRIPTION
Compare the tension in the string when the cart is stationary to that when the system is accelerated by the hanging weight:  Hold the cart stationary for a few seconds while LoggerPro plots the tension in the string.  Have students predict what will happen to the tension when the cart is released and then let it go.

The "Tension" experiment file is set to plot (smoothed) force vs time for 8 sec.

Have an assistant catch the cart before it crashes into the end stop.

NOTES

Use the 200 g mass as the hanging weight.  It is massive enough relative to the cart + force sensor to produce a significant difference in tension in the two cases, and not so heavy that the run is too short.

Use the "Tension" experiment file with the calibration info for the particular force sensor.  Zero the force sensor (using the software) when it is secured to the cart with no force on the hook.

Make sure the string is parallel to the track.  The setup is shown below: