Datalogging in Science

Acceleration of a body in free-fall

Overview

In this experiment, a “double interrupt card” is dropped through a single light gate. The time at which each break of the infrared beam occurs is recorded. With knowledge of the width of the interrupt card, the software can determine the velocities at key stages of the fall and use these increasing values of velocity to calculate acceleration. Several trials will be conducted and an average value found.

Procedure.
1. Assemble the apparatus as shown.

2. Connect the light gate to Input A on the datalogger.

3. Connect the datalogger to the computer and
launch the Timer program.

4. Set the Timing software to record Acceleration at A in repeat mode.

5. Enter the length of the segments on the interrupt card when prompted (the segment is the solid section of the card that will pass through the light gate).

6. Begin recording and then drop the interrupt card ensuring that the light beam is broken by each section of the card.

7. Repeat the experiment many times and when enough readings have been taken, stop recording by clicking on the red square.

7. Delete any obviously obscure measurements.

8. Save your results in the recommended folder

9. Calculate the average acceleration.

Precautions.

1. Ensure that the double-interrupt card falls in the required manner.

2. Don’t bring the interrupt card back through the gate to the starting point. (This would mislead the software).

Results

The acceleration due to gravity g = ________ (meters / second squared)

Questions

How does the software calculate acceleration?


Extensions


1. Investigate if the mass of a freely falling object affects its acceleration?

2. Investigate if the height from which the object fell affects its acceleration.

Data Harvest users

1. Connect the sensor to the datalogger and the logger to the computer
2. Then click the Set Up icon to the right of this message.
3. When the software opens, click the Play button.