Set up a picket fence timer

Use this timer to measure position, speed, and acceleration of a cart that has a picket fence attached. Also measure the acceleration due to gravity when dropping the picket fence through a photogate.

Equipment setup

• Photogate

  Use a Wireless Smart Gate (PS-3225), a Smart Gate (PS-2180) with a PASPORT interface, or a Photogate Head (ME-9498A) with a digital interface. Mount the photogate on a track if measuring the motion of a cart (upper image). Mount the photogate to a ring stand if measuring the acceleration due to gravity (lower image).

• Picket Fence

  Use either the Smart Timer Picket Fence (ME-8933) or Cart Picket Fence (ME-9804) if measuring the motion of a cart. Use the Picket Fence (ME-9377) if measuring the acceleration due to gravity.

Set up the timer

1. Connect your chosen photogate to Capstone.
2. Select Timer Setup from the Tools palette.
3. At the top of the Timer Setup tool, click the Delete button to delete the premade Smart Timer.
4. Select Pre-Configured Timer, then click Next.
5. Ensure that exactly one photogate is selected from the list of available timing devices, then click Next.
6. Select Picket Fence from the list of available timers.
7. Check the box for each measurements you want to be visible, then click Next.

8. Measure the distance between the leading edges of two flags, as shown below. Enter this value into the Flag Spacing text box, then click Next.

   

9. Give the timer a custom name, or use the default name, and click Finish.

Record data

Click Record , then let the entire picket fence pass through the photogate. The first time the photogate is blocked, it records a position of zero. The second time the photogate is blocked, it records the second position and the speed. The third time the photogate is blocked, it records the third position, the second speed measurement, and the acceleration.