Book One

Question 1

what is physical quantity? + examples

Answer 1

a quantity that can be measured, calculated, has a size and unit.
- length
-mass
-time

Question 2

prefixes

Answer 2

tetra - T - 10^12
giga - G - 10^9
mega - M - 10^6
kilo - k - 10^3
centi - C - 10^-2
milli - M - 10^-3
micro - µ - 10^-6
nano - n - 10^-9
pico - p - 10^-12

Question 3

base units

Answer 3

mass - M/m - kilogram - kg
length - L/l - metre - m
time - t - second - s
electric current - I - ampere - A
thermodynamic temperature - T - kelvin - K
amount of sub. - n - mole - mol
luminous intensity - n/a - candela - cd

Question 4

derived units

Answer 4

frequency(f) - Hz - s^-1
velocity(v) - ms^-1 - ms^-1
acceleration(a) - ms^-2 - ms^-2
force(F) - N - kgms^-2
energy(E) - J - kgm^2s^-2
power(P) - W -kgm^2s^-3
electric charge(Q) - C - As
p.d(V) - V - kgm^2s^-3A^-1
electrical resistance(R) - Ω - kgm^2s^-3A^-2
spec. heat capacity - Jkg^-1K^-1 - m^2s^-2K^-1

Question 5

what is a scalar quantity? + examples

Answer 5

a quantity that is defined by only magnitude (size)
- mass
- distance
- speed
- pressure
- density
- time
- temperature
- energy

Question 6

what is a vector quantity?

Answer 6

a quantity that is defined by both magnitude and direction
- weight
- displacement
- velocity
- force
- current
- force
- gravitational field strength

Question 7

what is a resultant vector?

Answer 7

the vector combination of two or more signle vectors

Question 8

equilibrium or coplanar vectors

Answer 8

when 3 coplanar forces acting at an angle to each other are added and form a triangle

Question 9

what are resolution of vectors?

Answer 9

2 vectors can be added together to give a resultant. the reverse is possible

Question 10

what is human error?

Answer 10

errors attributed to the experimenters skills and techniques. (include parallax and zero errors)

Question 11

what is zero error?

Answer 11

error in reading of a measuring instrument which does not start at the zero mark. e.g. metre rule thats worn out at the edge

Question 12

what is accuracy?

Answer 12

the degree to which a measured value approaches the true value

Question 13

what is precision?

Answer 13

the consistent results of repeated measurements regardless of how close they are to the true value

Question 14

how to calculate uncertainties (just read and remember)

Answer 14

a = b + c then △a = △b + △c
a = b - c then △a = △b + △c
a = kbc then △a/a = △b/b + △c/c
a = kb^xc^y then △a/a = x(△b/b)+y(△c/c)

Question 15

what is parallax error?

Answer 15

an error due to incorrect positioning of the experimenter when reading the apparatus