1. Realm of physics
SI units – fundamental – kg, s, m, amp, mole, K
-derived – Newton composed of kg, s, m
- watt, joule, coulomb, volt, ohm
Kg2 lb myard N apple
Orders of magnitude – powers of ten

2. In the study of the motion of fluids we often refer to their
“viscosity” (symbol η). The following formula gives a method
of measuring viscosity
F = 6πηrv
F represents a force
r represents a distance
v represents a velocity
This means that the units of viscosity (η) are
A. Ns-1m-2
B. Nm-2s
C. N-1m2s-1
D. kgm-2s

3. Error
•systematic - caused by flawed devices, uncalibrated,
cannot be reduced by more trials, affects the
accuracy
Evidence: a graph that should hit the origin is off
2) random - affects the precision, more trials can
help this
Evidence – points are scattered around the best fit
line

4. Uncertainties
How determined:
analog (meterstick, grad cyl)- half the smallest division
digital – the smallest scale division
Uncertainty in a calculated value = sum of % uncertainties

5. Uncertainty in mass is 5%, speed is 10%
What is the uncertainty in momentum (p=mv) and
kinetic energy (1/2 mv2)?
The lengths of the sides of a 5 0 ± 0 ·5 m m
rectangular plate are measured,
and the diagram shows the 2 5 ± 0 ·5 m m
measured values with their
uncertainties.
Which one of the following would be the best
estimate of the percentage uncertainty in the
calculated area of the plate?
A. ±0·02%
B. ±1%
C. ±3%
D. ±5%

6. Vector Scalar
Displacement Distance
Velocity Speed
Acceleration Mass
Force Energy
Momentum Temp
Any field strength Voltage
Adding and subtracting – tip to tail
Resolving into components

7. Which one of the following is not a
vector quantity?
A. velocity
B. work
C. weight
D. acceleration.

8. Masses (kg)
Universe 1050
Sun 1030
Earth 1024
Virus 10-21
Hydrogen atom 10-27
Electron 10-30

9. Lengths (m)
Distance to edge of universe 1026
Distance to nearest star 1016
Diameter of solar system 1013
Distance to sun 1011
Radius of earth 107
Size of hydrogen atom 10-10
Size of nucleus 10-15
Size of proton 10-17

10. Time (s)
Age of universe 1018
Age of earth 1017
Time of travel by light to nearest star 108
One year 107
One day 105
Period of a heartbeat 1
Period of red light 10-15
Passage of light across a nucleus 10-24