Question 18M.3.HL.TZ2.19
| Date | May 2018 | Marks available | [Maximum mark: 6] | Reference code | 18M.3.HL.TZ2.19 |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Explain, Outline | Question number | 19 | Adapted from | N/A |
Explain the evidence that indicates the location of dark matter in galaxies.
[3]
«rotational» velocity of stars are expected to decrease as distance from centre of galaxy increases
the observed velocity of outer stars is constant/greater than predicted
implying large mass on the edge «which is dark matter»
OWTTE
1st and 2nd marking points can be awarded from an annotated sketch with similar shape as the one below
[3 marks]
Outline why a hypothesis of dark energy has been developed.
[3]
data from type 1a supernovae shows universe expanding at an accelerated rate
gravity was expected to slow down the expansion of the universe
OR
this did not fit the hypotheses at that time
dark energy counteracts/opposes gravity
OR
dark energy causes the acceleration
OWTTE
[3 marks]