The photogate measures speed by timing how long it takes for a "flag" to block an infrared beam of light.
You measure the "flag" to be 2 cm long with a vernier caliper that has an uncertainty of 0.01 cm.
The Capstone software tells you that the velocity of the flag was 5.714 m/s and it can measure time with an uncertainty of 0.1 ms.
How long was the flag blocking the beam? What is the uncertainty in that velocity?