The most likely reason for wanting this would be to plot the motion of two carts in a collision. There are three ways to handle this as noted below. All three options require an additional purchase; they are listed below in order from least expensive to most expensive.

OPTION 1
The least expensive method is to use a motion encoder cart and receiver from a second dynamics cart and track system with motion encoder that you already own. The down side is that you would only have half as many stations for your students to use.

You will need to purchase and install a second motion encoder strip on the tracks that will use the two encoder carts. Each strip you purchase is enough for two 1.2 meter tracks or one 2.2 meter track.

OPTION 2
You can upgrade one of your existing carts that does not have the encoder sensor, such as the plunger cart. The upgrade kit includes the hardware necessary to convert one cart, a motion encoder receiver, and the encoder tape mentioned in Option 1.

You will need to purchase an upgrade kit for every lab station for which you want to use two encoder carts per track.

OPTION 3
You can purchase an additional motion encoder cart and receiver for use with your systems. The additional cart includes the encoder tape as noted in Option 1 above.

You will need to purchase an extra cart for every lab station for which you want to use two encoder carts per track.

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Can I buy a plunger-equipped encoder cart?