AQA
A Level
A Level Physics
Particles (Answers)
Total Marks:/30
, 1. This question explores the fundamental forces that are invoked in the standard model and that act at
the quantum level.
Total for Question 1: 10
(a) State the three fundamental interactions that are described by the Standard Model. [2]
Solution: Electromagnetic, strong nuclear, weak
(b) Describe the nature of the strong nuclear force and sketch a graph to show its variation with [4]
distance.
Solution: It acts between all nucleons but is effective only at very short range. It is repulsive
below 0.5 fm and attractive between about 0.5 and 3 fm.
Sketch of F against r should illustrate the above. Global minimum between 0.5 and 3 fm;
tending towards zero with increasing r; tending to infinity at low r.
Page 2
A Level
A Level Physics
Particles (Answers)
Total Marks:/30
, 1. This question explores the fundamental forces that are invoked in the standard model and that act at
the quantum level.
Total for Question 1: 10
(a) State the three fundamental interactions that are described by the Standard Model. [2]
Solution: Electromagnetic, strong nuclear, weak
(b) Describe the nature of the strong nuclear force and sketch a graph to show its variation with [4]
distance.
Solution: It acts between all nucleons but is effective only at very short range. It is repulsive
below 0.5 fm and attractive between about 0.5 and 3 fm.
Sketch of F against r should illustrate the above. Global minimum between 0.5 and 3 fm;
tending towards zero with increasing r; tending to infinity at low r.
Page 2
