PASCO ME-8930 SMART TIMER - Manual (Page 20)

Smart Timer 012–06734A
16
Questions
1. How do the two methods for determining the acceleration on a body due to Earth’s
gravity compare?
2. How do the experimental measurements compare to accepted values?
2. Insert the plug of the photogate into channel 1 or 2 of the Smart Timer, and set up the
Smart Timer to measure Time, Fence.
3. Hold the Smart Timer Picket Fence in a position so it will drop vertically through the
photogate and so the 5 cm fence will block the photogate beam as the fence drops
through the photogate.
Note: Three conditions must be met for greatest accuracy:
1. The Picket Fence must be dropped at a 90º angle to the photogate beam in such a
way that it does not rotate on the way down. One method to improve the drop is to
hold the edge of the Picket Fence with a clothspin or binder clip, and drop the
fence by squeezing the clothespin or clip.
2. The Picket Fence must be dropped so the 5 cm marks cut the photogate beam.
3. The Picket Fence must pass close to the LED that emits the photogate beam.
4. Press and drop the fence.
5. Record t
1
and t
2
, and calculate the acceleration in meters/second 2 .
PART B—Determining the acceleration directly.
1. Repeat steps 1 – 4 in Part A with the following modification: Set the Smart Timer to
measure Acceleration: One Gate. Repeat several times and calculate the average
acceleration (g).