Objective: To investigate the relationship between FnetT² and radius Proposed Hypothesis: FnetT² is directly proportional to the radius Manipulated variable: Radius of the circular motion
Responding variable: The time taken for 20 rotations
Controlled variables: The mass of the rubber stopper, the mass of the weight hanger, the total weight of the slotted weight, the length of the PVC tube Apparatus and Materials: rubber stopper, stopwatch, weight hanger, slotted weights,
crocodile clip, metre rule, thread, PVC tube
Procedure: 1. Weigh and record the masses of weight hanger and rubber stopper.
2. Tie the thread to the rubber stopper.
3. Pass the thread through the PVC tube.
4. Tie a node at the end of the thread and hang the weight hanger which is with
0.08g slotted weights on it.
5. Measure the 0.1m radius from the bottom of PVC tube and mark it.
6. Zheng Yie starts to rotate the thread with an acceleration until the bottom of
PVC tube is reached the mark.
7. Keep the speed of rotation constant so that the bottom of PVC tube is
always touched the mark.
8. After the speed is kept at constant speed, Adeline starts to studies the time
taken for 20 rotations by using a stopwatch.
9. Adeline is also responsible to record the time taken for 20 rotations.
10. Step 5 until step 9 are repeated by using different radii such as 0.2m, 0.3m,
0.4m, 0.5m, 0.6m, 0.7m, 0.8m, and 0.9m.
11. The experiment is repeated once again and take the average of the two of
the results as the final result.
Radius, r (m)| Time for 20 rotations, (s)| Time for 1 rotation, T (s)| T² (s²)| FnetT² (Ns²)| | Reading 1| Reading 2| Average| | | |
0.1| 05:37| 05:69| 05:53| 0:28| 0.078| 0.076|
0.2| 06:37| 06:94| 06:66| 0:33| 0.109| 0.106|
0.3| 07:44| 08:19| 07:82| 0:39| 0.152| 0.150|