2. Foundations in physics

Question 1

What are the 6 SI base units you need to know?

Answer 1

length / m
mass / kg
time / s
electric current / A
temperature / K
amount of substance / mol

Question 2

List all of the prefixes

Answer 2

peta P 15
tera T 12
giga G 9
mega M 6
kilo k 3
deci d -1
centi c -2
milli m -3
micro u -6
nano n -9
pico p -12
femto f -15

Question 3

List 12 common derived units

Answer 3

Area / m2
Volume / m3
Acceleration / ms-2
Density / kgm-3

Force / kgms-2
Pressure / Nm-2
Energy or Work done / Nm
Power / Js-1
Potential difference / JC-1
Resistance / VA-1
Electric charge / As
Frequency / s-1

Question 4

Define Scalar quantity

Answer 4

A quantity that has a magnitude but no direction

Question 5

Define Vector quantity

Answer 5

A quantity that has both magnitude and direction

Question 6

What is the absolute uncertainty from a range of numbers?

Answer 6

Half of the range

Question 7

What is the absolute uncertainty of a device?

Answer 7

The smallest scale it measures

Question 8

How do you calculate percentage uncertainty?

Answer 8

absolute uncertainty / value x 100%

Question 9

How do you calculate percentage uncertainty from a graph?

Answer 9

gradient of best line - gradient of worst line / gradient of best line x100%

Question 10

How do you calculate absolute uncertainty from a graph?

Answer 10

Gradient of best line - gradient of worst line