Aim:
To determine the value of gravitation acceleration using the motion of a pendulum. Identify the causes in variation of this value.
Equipment: * Slotted Weight * Retort Stand * Sticky Tape * Clamp * String * 1 metre ruler * Timer
Method: * 1. Gather required equipment. * 2. Place retort stand onto table and tightly secure the clamp * 3. Tie the slotted weight onto one end of the string, and wrap the other end around the end of the clamp. * 4. Using a piece of sticky tape, secure the string onto the clamp. * 5. Using the ruler, measure and record the length of the string. * 6. Move the weight in a direction parallel to the bench’s edge and no more than 15 degrees. * 7. Release and begin timing simultaneously. * 8. Each complete oscillation, record the time taken. * 9. Repeat for 10 oscillations. * 10. Shorten string to desired amount and repeat. * 11. Repeat steps 5-10 a further 4 times.
Analysis:
Result Table:
Length (m) | T (seconds) | T² (seconds) | m (gradient) | g (ms^-2) | 0.461 | 1.5 | 2.25 | 4.880694143 | 8.08868912 | 0.586 | 1.64 | 2.6896 | 4.589761092 | 8.601410144 | 0.689 | 1.75 | 3.0625 | 4.444847605 | 8.881838281 | 0.793 | 1.86 | 3.4596 | 4.362673392 | 9.049134342 | 0.877 | 1.88 | 3.5344 | 4.030102623 | 9.795883954 |
Average value for m (gradient): 4.46
Average value for g (ms^-2): 8.88 ms^-2
The accepted value of gravity on Earth is 9.8 ms^-2
Accuracy: |8.88 – 9.80| / 9.80 x 100 = 9.39 = Percentage of error
Therefore the degree of accuracy is 90.6%.
This shows that our experiment was fairly inaccurate.
Reliability: Furthest value from the average 8.88 ms^-2 is 9.80 ms^-2 |8.88-9.80| = 0.92 0.92/8.88 = 10.36%
Therefore this experiment is unreliable.
Discussion:
From previous calculations and the graph, we can see that the experiment performed is both inaccurate and unreliable. The