Question 19M.2.HL.TZ1.b.iii
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.2.HL.TZ1.b.iii |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Sketch | Question number | b.iii | Adapted from | N/A |
A small metal pendulum bob is suspended at rest from a fixed point with a length of thread of negligible mass. Air resistance is negligible.
The pendulum begins to oscillate. Assume that the motion of the system is simple harmonic, and in one vertical plane.
The graph shows the variation of kinetic energy of the pendulum bob with time.
When the 75 g bob is moving horizontally at 0.80 m s–1, it collides with a small stationary object also of mass 75 g. The object and the bob stick together.
Sketch, on the axes, a graph to show the variation of gravitational potential energy with time for the bob and the object after the collision. The data from the graph used in (a) is shown as a dashed line for reference.
[2]
graph with same period but inverted ✔
amplitude one half of the original/two boxes throughout (by eye) ✔
Many candidates drew graphs that received one mark for either recognizing the phase difference between the gravitational potential energy and the kinetic energy, or for recognizing that the total energy was half the original energy. Few candidates had both features for both marks.
