Lab 1 - Determine the Velocity of a Constant Velocity Car
Introduction
Velocity is defined as changing position with respect to time. For an object to moving with constant velocity, the displacement between two points needs to the same for every time interval.
In this we investigated the concept of constant velocity by taping a piece of timer tape to a battery, powered constant velocity car. On the timer tape, if the car was truly going constant velocity, the dots would be spaced out evenly. After creating a data table from the timer tape, a position vs. time graph was created. Constant velocity on a position vs. time graph is a linear relationship, with the slope of the line being the average velocity of the car.
Understanding constant velocity is crucial as it forms the basis for more complex topics in physics, such as acceleration and forces. This lab not only reinforced theoretical knowledge but also provided hands-on experience in data collection, analysis, and interpretation, which are essential skills in scientific inquiry.
Purpose
To determine the average velocity of a constant velocity car by using the five reperesentations of motion.
Figure 1 - Lab setup for Constant Velocity car lab
Figure 2. Measuring displacement of the constant velocity car.
To investigate the constant velocity of a car, a spark timer was utilized to record the car's motion over a fixed distance. Timer tape was strung through the back of the spark timer and tape to the back end of the car. The car was placed at the starting line, and the spark timer was set to create sparks at regular time intervals (10 Hz) as the car moved. The constant velocity car was turned on and allowed to travel down the table. As the car traveled along the table, the spark timer marked its position on a strip of tape, leaving a series of dots that represented the car’s position at each time interval. After the car completed its course, the distance between consecutive dots on the tape was measured to determine the car's displacement over each time interval (Figure 2). This process created a position-time data table. Once the table was created, a position-time graph was developed to determine the avearge velocity of the car.
Results/Data
During the experiment, data was collected by measuring the distance between the consecutive dots produced by the spark timer, which represented the car's position at equal time intervals. The time interval between each dot was set to 0.1 seconds. The following table shows the measured distances (in meters) for each time interval. The following position vs. time graph was created from the data table.
Data Table 1. Position-Time data for constant velocity car
Graph 1. Position vs. Time Graph for Constant Velocity vehicle
Discussion/Analysis
From the table, it is clear that the displacement between each time interval remained consistent for the trip of the constant velocity car. From the trendline on the position vs time graph, the constant velocity of the vehicle is 0.205 m/s.
Conclusions
The constant velocity car lab successfully demonstrated the concept of uniform motion. By analyzing the data collected from the spark timer, we observed that the car traveled equal distances in equal time intervals, resulting in a consistent velocity throughout the experiment. The calculated velocity remained constant, which was further confirmed by the straight line observed in the velocity vs. time graph.
These results align with the theoretical understanding of constant velocity, where an object in motion maintains the same speed in a straight line if no external forces act upon it. The experiment provided a practical understanding of how velocity can be calculated and analyzed using simple tools and techniques.
In summary, the lab reinforced key concepts in kinematics, particularly the relationship between distance, time, and velocity. It also highlighted the importance of precise data collection and analysis in verifying physical principles. The consistent results obtained underscore the reliability of the methods used and the accuracy of the spark timer as a tool for measuring motion.
One source of error for the lab is the height difference between the timer tape and the back of the car. This error could have created a little friction, slowing the car down. To fix the source of error, place the spark timer on a box that levels out the timer tape and the back of the car. Another source of error is the timer tape was not attached to the center of the back of the car. This could cause the dots and the car to travel at a diagonal to the spark timer. To ccrrect this source of error, measure the location of the middle of the car and place the tape at this location.