If there is no balance, do we measure the mass of the object with air rail and stored digital millisecond meter, and briefly describe its steps?

There are many kinds of rice. I don't know which one you are talking about. If it is the longest, you can install a U-shaped fork on the slider and adjust the leveling screw of the air cushion guide rail to make it have a certain angle and a certain initial speed. Put the slider on the guide rail and read the distance from the highest point to the instrument probe. From the readings of the U-fork and the instrument, the initial velocity and acceleration in the inclined plane direction can be obtained in the whole process. I don't have to worry about the rest.