DP Physics (last assessment 2024)
Question 19M.3.HL.TZ2.13b
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.HL.TZ2.13b |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Explain | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
19M.3.HL.TZ2.13b
A solid sphere is released from rest below the surface of a fluid and begins to fall.
(b)
Explain why the sphere will reach a terminal speed.
[2]
Markscheme
«as the ball falls» there is a drag force ✔
when drag force+buoyant force/upthrust =«-» weight
OR
When net/resultant force =0 ✔
«terminal speed occurs»
OWTTE
Terminal speed is mentioned in the question, so no additional marks for reference to it.
Examiners report
Many candidates could explain correctly that the drag force would increase as the speed increases and that the weight would be balanced by the buoyant force and the drag force.
