Question 19M.3.SL.TZ1.a
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.SL.TZ1.a |
| Level | SL | Paper | 3 | Time zone | TZ1 |
| Command term | Suggest | Question number | a | Adapted from | N/A |
In an investigation a student folds paper into cylinders of the same diameter D but different heights. Beginning with the shortest cylinder they applied the same fixed load to each of the cylinders one by one. They recorded the height H of the first cylinder to collapse.
They then repeat this process with cylinders of different diameters.
The graph shows the data plotted by the student and the line of best fit.
Theory predicts that H = where c is a constant.
Suggest why the student’s data supports the theoretical prediction.
[2]
theory «» predicts that H3 ∝ D2 ✔
graph «of H3 vs D2 » is a straight line through the origin/graph of proportionality ✔
Allow gives H3 = c3D2 for MP1.
Do not award MP2 for “the graph is linear” without mention of origin.
Load on a cylinder. The question was successful for candidates well prepared to write conclusions in their lab reports. Theory in the stem of the question predicts a directly proportional relationship between H and D2/3, which graphed are H3 and D2. Well prepared candidates were able to identify, that the theory predicts that H3 should be directly proportional to D2 and that this proportionality can be seen from the graph. Many candidates were able to mention that the relationship was linear and passed through the origin (as an alternative to proportional). However, a common response mentioned only linear or linear regression which is not sufficient to fully demonstrate proportionality.
