Dy
Physics
CH 1
Terms:
● Mechanics: the study of the motion of objects and the forces acting on them;
sub-branches of mechanics include kinematics, dynamics and statics
● Kinematics: a branch of mechanics involving the analysis of motion while
neglecting the forces responsible for motion
● Dynamics: a branch of mechanics involving the analysis of motion while focussing
on the forces responsible for the motion
● Statics: a branch of mechanics focussing on the forces acting on an object that is at
rest
● Scalar measure: refers to à measurement/quantity described only by à magnitude (
value), no direction (ex. Distance, speed, acceleration)
● Vectorial measure: refers to à measurement/quantity described by both à
magnitude and a direction ( ex. Displacement, velocity, acceleration)
● Distance: a scalar measure of total distance travelled by an object during à journey
regardless of direction
● Displacement: a vectorial measure of the direction separating the start and end
points of a journey, and includes a direction of motion
● Average speed: à scalar measure referring to the total distance travelled over à
period of time
● Average velocity: à vectorial measure referring to the displacement over à period
of time
● Acceleration: à scalar/vectorial measure referring to the change in speed/velocity
over à period of time, and includes à direction of motion if the acceleration is
vectorial
● Position: relates to an origin, or à reference point, or à reference system and is
relevant when dealing with vectorial measures
● Vector: refers to an arrow drawn to scale, whereby its length indicates the
measure’s magnitude and its orientation indicates the measure’s direction
● Instantaneous speed/velocity: à measure of speed/velocity at à particular point in
time; can be found by interpolating of extrapolating from à Speed/Velocity vs. Time
graph, or by finding the slope of the tangent on à Distance/Position vs. Time graph
● Standard reference system: used when working with vectorial quantities and
includes the Cartesian grid, or the polar grid (N,S,E,W) or up (+) down (-) or right
(+) left (-)
,Dy
Metric prefixes:
Factor Prefix Symbol
10^18 exa E
10^15 peta P
10^12 tera T
10^9 giga G
10^6 mega M
10^3 kilo k
10^2 hecto h
10^1 deka da
10^0 Unit of measure
10^-1 deci d
10^-2 centi c
10^-3 mili m
10^-6 micro µ
10^-9 nano n
10^-12 femto f
10^-15 atto a
Significant Digits:
The number of significant digits relates to the accuracy of the measurement and/or device
-à significant digit is: any
- non zero number
- any zero between non-zero numbers (ex. 203 has three sig. figs.)
- any trailing zero after à decimal (ex. 2.40 has three sig. figs.)
-any trailing zero before à decimal if the value is à known measurement
(ex. The 100m dash has three sig. Figs. because this is à known and exact measure’ the
distance between room 303 ant the main doors is 100m long has 1 sig. fig. because it isn't
à known and exact measure and is only accurate to the nearest hundreds)
- When working with numbers, the answer cannot become more precise than the
least accurate number that you worked with
Ex. 3.3 x 2.51 = 8.283
two three four
,Dy
You cannot become more accurate by multiplying, dividing, adding or subtracting numbers,
therefore, the correct answer would have to be rounded to the least accurate value...2 sig.
figs. Meaning that the correct answer is 8.3
Rounding:
- If the trailing number is greater than 5, you round up
- If trailing number is less than 5, you leave it alone
- If the trailing number is 5 you round up if doing so makes it an even number BUT
you leave it alone is rounding up makes it an odd number
- Ex. round each number to the nearest tenth.
2.44 = 2.44
2.45 = 2.45
2.55 = 2.6
2.56 = 2.6
Converting Units:
Measure of Time
1a = 365.25 days
1d = 24h
1h = 60min
1m = 60sec
Measures of length
1cm = 0.4” or 1” = 2.5cm
1m = 3.3’ or 1’ = 0.3m
1km = 0.6mi or 1mi = 1.6km
Measures of Volume
1L = 0.3gal or 1gal = 3.8L
Measure of Mass
1g = 0.04oz or 1oz = 28.3g
1kg = 2.2lb or 1lb = 0.4kg
Questions:
1. If you travelled 30km [N], then 40km [E] in a period of 1h:
A) 70k
B) 70km/h
C) 50[N53E]
D) 50 km/h (N53EI)
2. Explain the difference between instantaneous speed and average speed.
, Dy
a) Average speed is the speed you go over a period of time like 70km/h whereas
Instantaneous is speed at a particular point in time.
3.
- 96km/h time of 4.9s
- 240 km/h
- 10.1km/L
4. State the number of significant digits for each of the following values:
a) 3211m = 4
b) 20 001cm = 5
c) 2 001 000mm = 4
d) 0.002kg = 1
e) 0.02000g = 1
f) 200.000mg = 6
5. Round each of the following values to the nearest tenth.
a) 3.123 = 3.1
b) 3.25 = 3.2
c) 3.35 = 3.4
d) 3.55 = 3.6
e) 3.350 000 = 3.4
f) 3.5 = 3.5
6.
a) 2.301 + 1.444 = 3.745
b) 321.
c)
d)
e)
f) 1.2 x 3.33 = 3.91
g) 1/1.3 = 0.77
h) 1/0.3 = 3.3
i) ⅓ = 0.33
j) ⅓ = 0.33
k)1.45 x 5.5 = 7.9
Physics
CH 1
Terms:
● Mechanics: the study of the motion of objects and the forces acting on them;
sub-branches of mechanics include kinematics, dynamics and statics
● Kinematics: a branch of mechanics involving the analysis of motion while
neglecting the forces responsible for motion
● Dynamics: a branch of mechanics involving the analysis of motion while focussing
on the forces responsible for the motion
● Statics: a branch of mechanics focussing on the forces acting on an object that is at
rest
● Scalar measure: refers to à measurement/quantity described only by à magnitude (
value), no direction (ex. Distance, speed, acceleration)
● Vectorial measure: refers to à measurement/quantity described by both à
magnitude and a direction ( ex. Displacement, velocity, acceleration)
● Distance: a scalar measure of total distance travelled by an object during à journey
regardless of direction
● Displacement: a vectorial measure of the direction separating the start and end
points of a journey, and includes a direction of motion
● Average speed: à scalar measure referring to the total distance travelled over à
period of time
● Average velocity: à vectorial measure referring to the displacement over à period
of time
● Acceleration: à scalar/vectorial measure referring to the change in speed/velocity
over à period of time, and includes à direction of motion if the acceleration is
vectorial
● Position: relates to an origin, or à reference point, or à reference system and is
relevant when dealing with vectorial measures
● Vector: refers to an arrow drawn to scale, whereby its length indicates the
measure’s magnitude and its orientation indicates the measure’s direction
● Instantaneous speed/velocity: à measure of speed/velocity at à particular point in
time; can be found by interpolating of extrapolating from à Speed/Velocity vs. Time
graph, or by finding the slope of the tangent on à Distance/Position vs. Time graph
● Standard reference system: used when working with vectorial quantities and
includes the Cartesian grid, or the polar grid (N,S,E,W) or up (+) down (-) or right
(+) left (-)
,Dy
Metric prefixes:
Factor Prefix Symbol
10^18 exa E
10^15 peta P
10^12 tera T
10^9 giga G
10^6 mega M
10^3 kilo k
10^2 hecto h
10^1 deka da
10^0 Unit of measure
10^-1 deci d
10^-2 centi c
10^-3 mili m
10^-6 micro µ
10^-9 nano n
10^-12 femto f
10^-15 atto a
Significant Digits:
The number of significant digits relates to the accuracy of the measurement and/or device
-à significant digit is: any
- non zero number
- any zero between non-zero numbers (ex. 203 has three sig. figs.)
- any trailing zero after à decimal (ex. 2.40 has three sig. figs.)
-any trailing zero before à decimal if the value is à known measurement
(ex. The 100m dash has three sig. Figs. because this is à known and exact measure’ the
distance between room 303 ant the main doors is 100m long has 1 sig. fig. because it isn't
à known and exact measure and is only accurate to the nearest hundreds)
- When working with numbers, the answer cannot become more precise than the
least accurate number that you worked with
Ex. 3.3 x 2.51 = 8.283
two three four
,Dy
You cannot become more accurate by multiplying, dividing, adding or subtracting numbers,
therefore, the correct answer would have to be rounded to the least accurate value...2 sig.
figs. Meaning that the correct answer is 8.3
Rounding:
- If the trailing number is greater than 5, you round up
- If trailing number is less than 5, you leave it alone
- If the trailing number is 5 you round up if doing so makes it an even number BUT
you leave it alone is rounding up makes it an odd number
- Ex. round each number to the nearest tenth.
2.44 = 2.44
2.45 = 2.45
2.55 = 2.6
2.56 = 2.6
Converting Units:
Measure of Time
1a = 365.25 days
1d = 24h
1h = 60min
1m = 60sec
Measures of length
1cm = 0.4” or 1” = 2.5cm
1m = 3.3’ or 1’ = 0.3m
1km = 0.6mi or 1mi = 1.6km
Measures of Volume
1L = 0.3gal or 1gal = 3.8L
Measure of Mass
1g = 0.04oz or 1oz = 28.3g
1kg = 2.2lb or 1lb = 0.4kg
Questions:
1. If you travelled 30km [N], then 40km [E] in a period of 1h:
A) 70k
B) 70km/h
C) 50[N53E]
D) 50 km/h (N53EI)
2. Explain the difference between instantaneous speed and average speed.
, Dy
a) Average speed is the speed you go over a period of time like 70km/h whereas
Instantaneous is speed at a particular point in time.
3.
- 96km/h time of 4.9s
- 240 km/h
- 10.1km/L
4. State the number of significant digits for each of the following values:
a) 3211m = 4
b) 20 001cm = 5
c) 2 001 000mm = 4
d) 0.002kg = 1
e) 0.02000g = 1
f) 200.000mg = 6
5. Round each of the following values to the nearest tenth.
a) 3.123 = 3.1
b) 3.25 = 3.2
c) 3.35 = 3.4
d) 3.55 = 3.6
e) 3.350 000 = 3.4
f) 3.5 = 3.5
6.
a) 2.301 + 1.444 = 3.745
b) 321.
c)
d)
e)
f) 1.2 x 3.33 = 3.91
g) 1/1.3 = 0.77
h) 1/0.3 = 3.3
i) ⅓ = 0.33
j) ⅓ = 0.33
k)1.45 x 5.5 = 7.9
