Question 22M.2.HL.TZ1.7c.ii
| Date | May 2022 | Marks available | [Maximum mark: 2] | Reference code | 22M.2.HL.TZ1.7c.ii |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Deduce | Question number | c.ii | Adapted from | N/A |
Two identical positive point charges X and Y are placed 0.30 m apart on a horizontal line. O is the point midway between X and Y. The charge on X and the charge on Y is +4.0 µC.
A positive charge Z is released from rest 0.010 m from O on the line between X and Y. Z then begins to oscillate about point O.
Deduce whether the motion of Z is simple harmonic.
[2]
ALTERNATIVE 1
motion is not SHM ✓
«because SHM requires force proportional to r and» this force depends on ✓
ALTERNATIVE 2
motion is not SHM ✓
energy-distance «graph must be parabolic for SHM and this» graph is not parabolic ✓
This was a challenging question for candidates. Most simply assumed that because the charge was oscillating that this meant the motion was simple harmonic. Some did recognize that it was not, and most of those candidates correctly identified that the relationship between force and displacement was an inverse square.
