2. Connect the paper tape passing through the timer to the car. When operating, pay attention to clamp the paper tape on the car to avoid loosening the paper tape when the car moves. You can clamp it with a spring clip, but don't damage the paper tape to avoid breaking it when the car starts.
3. Connect the rope with heavy objects to the trolley through the pulley.
4. When operating, be sure to make the tension of the string pass through the center of gravity of the car to avoid the car from rotating or shaking when moving forward. After tying the wire, try to pull the car and see if it moves in a straight line.
5. Connect the dot timer to the power supply and let the car move on the horizontal long board; The dot timer starts working at the same time, and a series of dots are punched on the paper tape. When operating, type as many times as possible, and don't type the dots too closely or too loosely. If it is too dense, you can increase the weight tied under the pulley rope, otherwise it will be reduced.
6. Take off the paper tape, discard the dense dots at the beginning, and find a starting point at the back where it is easy to measure, taking the time of every five times as the time unit, that is, t = 0.02 * 5s = 0.1s. Starting from the first point on the paper tape, mark 0, 1, 2, 3, ... every 5 o'clock. Let the distance between two adjacent counting points be s 1', S2', S3', ...
7. Measure the displacements s 1', s2', s3', ..., and calculate the difference between two adjacent displacements △s 1=s2'-s 1', △s2=s3'-s2', △s3=s4'-s3', ...
8. calculate the acceleration a 1, a2, a3, ... by the formula A = △ s/t 2.
9. Find the acceleration a 1, a2, a3, ... that is, the acceleration of a car moving in a straight line at a constant speed.