Physics Lab Report How does the length of a string holding a pendulum affect its oscillation? Method 1. You will need the following apparatus: a pendulum, a piece of string, a clamp, a clamp stand and a timer. 2. Measure out CACM and attach the metal ball. 3. Establish an angle and let the ball swing for 10 oscillations, timing it and stopping at the 10th one. 4. Write down your results. 5. Repeat steps 2-4 another 2 times so that your results are reliable. 6. Then change the length of the string 4 times, so that you get 5 different sets of results and for each time, repeat it 3 times.
DC Raw Data Data Processing Calculations: example: (0. 89+0. 83+0. 89)/3 = 0. 87 I calculated the absolute uncertainty by considering the furthest point from the mean. For example: 1. 31 (mean) – 1. 25 (furthest point from the mean) = 0. 06 Therefore my absolute uncertainty is +1- 0. 06 I calculated the percentage uncertainty by dividing the absolute uncertainty by the mean and multiplying it by 100, like this: (0. 03/1. 70) Source of uncertainties: The uncertainties in the measurement came primarily from the equipment.
There is no sign of a considerable systematic error in this experiment. To improve the accuracy we could: Stretch out the piece of string along a flat table with a meter ruler beside it and mark the points where we wanted to hang the pendulum from. Use a clamp and a stand to release the ball every time to avoid human error Measure the angle from which we dropped the ball every time. Carry out the experiment in a vacuum, so that air resistance does not interfere. Precision & Reliability Figure 1 shows that most of my points lie really close to the best fit line. This proves that my results are precise.
However, the points did not all lie in a straight line, showing human error. Even though we repeated each time three times, we could have repeated it 5 or 10 times in order to get more results and create a more precise average. My results were reliable because I took three trials for each height, and took 5 heights. However, we could repeat them 10 times in order to be more reliable and we could use better equipment, like stronger string and a new ball and we could operate it on top of a surface with not so many things around it, that caused the ball to hit them a few times, forcing us to repeat the trial.
I wasn’t able to add these increments u to time and material constrictions. Limitations Limitation Effect on data/graph Improvement next time Swings of ball Couldn’t check that the ball came back to its original position every time. Use a sensor to check that the ball returns to its original position. Space The ball would sometimes hit the table when it was swinging, forcing us to start over, losing both time and accuracy Perform the experiment in an open space Time If we had more time, we could have repeated the trails more times making it more accurate Use free time to continue experiments, more trials.
