1.
State what is meant by a galaxy.
[1 mark]
- billions of stars held by gravity
JD SCIENCE
P6 Global challenges
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by the solar system.
[1 mark]
- the Sun and objects in orbit
3.
State what is meant by fusion in stars.
[1 mark]
- hydrogen nuclei join to helium
4.
State what is meant by the life cycle of a star like the Sun.
[1 mark]
- protostar → main sequence → red giant → white dwarf
5.
State what is meant by red-shift.
[1 mark]
- light from distant galaxies is shifted to longer wavelength
6.
State what is meant by the Big Bang.
[1 mark]
- the universe began from a very hot dense point
7.
State what is meant by CMB.
[1 mark]
- cosmic microwave background
8.
State what is meant by orbital motion.
[1 mark]
- gravity provides the centripetal force
9.
State what is meant by weight on other planets.
[1 mark]
- W = mg, g is different
10.
State what is meant by a satellite.
[1 mark]
- an object in orbit
11.
Grace is asked about a galaxy in a OCR Physics paper.
(a) [2 marks]
- the Milky Way is ours
(b) [3 marks]
- stars orbit the centre
12.
Grace is asked about the solar system in a OCR Physics paper.
(a) [2 marks]
- planets, moons, asteroids, comets
(b) [3 marks]
- the Sun is a star
13.
Grace is asked about fusion in stars in a OCR Physics paper.
(a) [2 marks]
- releases energy
(b) [3 marks]
- why the Sun is stable: fusion vs gravity
14.
Grace is asked about the life cycle of a star like the Sun in a OCR Physics paper.
(a) [2 marks]
- mass decides the path
(b) [3 marks]
- more massive stars can form neutron stars or black holes
15.
Grace is asked about red-shift in a OCR Physics paper.
(a) [2 marks]
- evidence the universe is expanding
(b) [3 marks]
- more distant, greater red-shift
16.
Grace is asked about the Big Bang in a OCR Physics paper.
(a) [2 marks]
- supported by red-shift and CMB
(b) [3 marks]
- not an explosion in space but of space
17.
W on Earth 600 N, g=10. Mass
[3 marks]
- Final answer: 60 kg
18.
Weight on a planet where g=4 N/kg for that mass
[3 marks]
- Final answer: 240 N
19.
A radio signal travels 3×10⁸ m/s. Time to a probe 3×10¹¹ m away
[3 marks]
- Final answer: 1000 s
20.
Orbital speed 2000 m/s, radius 4.0×10⁶ m. Period T=2πr/v (leave in terms of π)
[3 marks]
- Final answer: 4000π s
21.
A star is 8 light-minutes away. Distance in light-seconds
[3 marks]
- Final answer: 480 light-seconds
22.
Red-shift: λ increases from 400 nm to 440 nm. Δλ/λ
[3 marks]
- Final answer: 0.10
23.
Grace carries out a OCR-style required practical linked to space physics. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24.
Grace carries out collecting valid data for space physics. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25.
Grace carries out drawing a graph for space physics. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26.
Grace carries out evaluating a method about space physics. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
(c) [2 marks]
- too few repeats
27.
Compare a galaxy with the solar system.
[4 marks]
- billions of stars held by gravity
- the Sun and objects in orbit
- give one linked difference
28.
Compare the solar system with fusion in stars.
[4 marks]
- the Sun and objects in orbit
- hydrogen nuclei join to helium
- give one linked difference
29.
Compare fusion in stars with the life cycle of a star like the Sun.
[4 marks]
- hydrogen nuclei join to helium
- protostar → main sequence → red giant → white dwarf
- give one linked difference
30.
Compare the life cycle of a star like the Sun with red-shift.
[4 marks]
- protostar → main sequence → red giant → white dwarf
- light from distant galaxies is shifted to longer wavelength
- give one linked difference
31.
Apply your knowledge of CMB to this situation: leftover radiation from the early universe
[3 marks]
- leftover radiation from the early universe
32.
Apply your knowledge of orbital motion to this situation: closer orbits are faster
[3 marks]
- closer orbits are faster