2022 IB Diploma Extended Essays

1 x Centripetal force apparatus 1 x Milk 1 x Food coloring 1 x Tape 1 x Beaker 1 x Ruler 1 x 20ml Measuring cylinder 1 x Retort stand 1 x Burette clamp 1 x Stopwatch 1 x Phone (with slow motion video feature)

3.2.3 Method Modification to equipment

The beaker was placed on the edge of the centripetal force apparatus and secured with tape. Different amounts of liquids were tested to maximize the range of the data, so that all speeds could be used and measured. The ruler was taped on the outer edge (refer to figure ()). This is to ensure that the change in height of the liquid is measured from the correct location consistently. Planned method Food colouring was added to a liquid and then a 20 ml aliquot was measured with a measuring cylinder. This aliquot was then added to the beaker secured to the apparatus. The retort stand was placed with the burette clamp close to the apparatus. The phone was then prepared to record slow motion video and placed into the burette clamp, then adjusted so the camera would record the best and easiest to read results. Next, the first speed was set on the dial and the video started. Once the apparatus is operating, five periods were measured from one given point using a stopwatch. The time for five periods was then recorded along with the height from the best image from the video. These past two steps were completed five times for each of the six speeds. 3.2.4 Amendments to Method The liquid that was used in this experiment was changed after initial tests from water to milk. This change was made due to milk having a higher viscosity, to simulate magma more effectively. This change was also to do with the visibility of the liquid, as the water was hard to read form the slow-motion videos.

3.2.5 Safety Equipment

Risk associated

Handling procedure

Retort stand (with phone and burette stand)

The base of a retort stand is very heavy and was placed elevated on a trolley to ensure the phone camera was level with the beaker for a more precise reading. This means

The retort stand must be properly supported from the base and carefully handled. The retort stand must also be securely balanced on the trolley before the phone is

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