Apparatus
A ball – A marble
A plastic rectangular tray – about 40cm by 25
Some sand – fills up to about 2/3 of the tray
2 Rulers – one for drop height (1m)
- one for measuring the depth (15cm)
Clamp and Stand
2 planks of wood – light wood/palsa (so that it doesn’t sink)
Splinters – 10 cm long and 0.3mm wide
Method:
- Fill in the tray with sand
- Flatten the sand with the help of one of the planks of wood so the sand levels up to about 2/3 of the tray.
- With the help of the ruler placed over the surface of the sand, drop the marble at an initial height of 10cm.
- Gently remove the ball from the sand so that the hole does not get any deeper
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Measure the depth from the bottom of the hole to the height of the crater. To do this, use the splinter and place it vertically, without any pressure, in the hole. Then, with the other plank of wood, place it horizontally so the is just leveled up with the crater and touching the splinter. Put a mark on the splinter, at the level of the underside of the plank of wood. If not sure, please look at the diagram. The arrow indicates where you should put your mark on the splinter. Then, measure, from the bottom of the splinter to the mark and record.
- Do 3 trials for this height (I suggest that you drop the ball 3 times, remember which hole is which trial, and then measure all of them with different splinters).
- Recover the sand so that it again, levels up to about 2/3 of the tray, using the same amount of compression as the previous one, with the plank of wood.
- Add 10cm to the drop height and drop for 3 trials, repeating steps 4-8 until you’ve reached a drop height of 60cm.
- You should record your information in the table shown below and then make a line graph, plotting height versus average depth.
Diagram:
Data Collection:
Data Presentation
Graph
Look on attached graph paper.
Conclusion and Evaluation Stage
Conclusion
When the drop height is changed, so does the measured depth. To be more precise, as the drop height increased, the depth of the hole increased as well (with some minor errors occurring in between the experiment.
The error in between, when we doing the trial of the drop height of 30cm, may have been a random error. But when looking at the graph, the drop height and the depth measured do not seem to be proportional to each other. If we try to draw a curve on it, it will then produce a “zig-zag” curve on the graph. This may have been due to the lack of accuracy during the experiment. At times, the marble hit the stand and clamp. But also, each trial made were not all the same. The compression of the sand was not accurate at all as the holes which were recovered with sand probably did not have an even compression upon them as the rest of the sand.
Evaluation
Materials
