Date | May 2019 | Marks available | 1 | Reference code | 19M.3.HL.TZ2.8 |
Level | Higher level | Paper | Paper 3 | Time zone | 2 |
Command term | Define | Question number | 8 | Adapted from | N/A |
Question
A proton has a total energy 1050 MeV after being accelerated from rest through a potential difference V.
Define total energy.
Determine the momentum of the proton.
Determine the speed of the proton.
Calculate the potential difference V.
Markscheme
total energy is the sum of the rest energy and the kinetic energy ✔
«p2 c2 = 10502–9382 therefore» p=472«MeVc–1»✔
✔
OR
«ms–1» ✔
V = 112 «MV» ✔
Examiners report
Generally well answered by most candidates. A common mistake was to define the total energy in the context of classical mechanics.
Most candidates seemed to have the right starting points but mistakes were often made in attempting to convert units. The energy-momentum equation is generally best answered using only ‘MeV’ based units.
An easy calculation, that was generally well answered.
Very few candidates realised that this question required a simple calculation using eV= KE = (γ-1)E.