b$)$ Describe one task in which a quantum computer might out perform traditional

computers. In your answer explain what physical principles the quantum device

exploits and the expected computational advantage it provides.

$[6$ marks$]$

$($c$)($i$)$ Explain how the kilogram was defined prior to $2019$ and the reasons for which

it needed to be redefined.

$($ii$)$ How is the kilogram defined now? Briefly describe how it is measured experi$-$

mentally.