Unit 1 - Kinematics

Question 1

Position

Answer 1

The straight line distance and direction of an object from a reference point (an origin). This tell us how far away it is from the origin, and which direction.
Symbol: d (Note: there is a vector sign!!)
Unit: m

Question 2

Distance

Answer 2

In physics, distance refers to the total length of the path traveled by an object, regardless of direction.
Symbol: Δd (Note: there is NO vector sign because it is scalar!!)
Unit: m
Δd = | d2 - d1 | + | d3 - d2 | + | d4 - d3 | + . . . (Note: there is NO vector sign on Δd, but there is on the rest!!)
^Where each “turning point” must be considered

Question 3

Displacement

Answer 3

Displacement (or change in position) is the straight line distance and direction from an initial position to a final position.
Δd = df - di (Note: there are vector signs on each of them!!)
^The intermediate positions along the way are irrelevant
Symbol: Δd (Note: there is a vector sign!!)
Unit: m

Question 4

Origin

Answer 4

Reference point; it is a random point that direction will be in reference to.

Question 5

Mechanics

Answer 5

The study of motion of objects

Question 6

Kinematics

Answer 6

Part of the study of motion

Question 7

Vector quantities

Answer 7

Vector quantities have magnitude (size) and direction

Question 8

Scalars

Answer 8

Scalars only have magnitude (no direction)

Question 9

Compass Rose (Cardinal Points)

Answer 9

This convention works well if you only are dealing with directions that are multiples of 22.5°
(N, NNE, NE, NEE, E, SEE, SE, SSE, S, SSW, SW, SWW, W, NWW, NW, NNW)

Question 10

Bearings

Answer 10

Used for navigation, we only five a 3-digit angle which represents the clockwise rotation from due north
(Ex: 078° means “rotate 78° clockwise from due North”

Question 11

Point-Angle-Point (PAP)

Answer 11

Point yourself in one of the 4 major directions, rotate a certain angle towards one of the other directions
(Ex: [E 35° S] means “aim east, rotate 35° towards the south”)
WE USE PAP CONVENTION!!

Question 12

Is position dependent on the origin we choose?

Answer 12

Yes

Question 13

Is displacement dependent on the origin we choose?

Answer 13

No

Question 14

Is distance dependent on the origin we choose?

Answer 14

No

Question 15

Velocity

Answer 15

Velocity is the rate of change of position with respect to time.
Symbol: V (Note: there is a vector sign!!)
Unit: m/s

Question 16

Speed

Answer 16

Speed is the rate of distance with respect to time.
Symbol: V (Note: there is NO vector sign because it is scalar!!)
Unit: m/s

Question 17

Acceleration

Answer 17

Acceleration is the rate of change of velocity with respect to time.
Symbol: a (Note: there is a vector sign!!)
Unit: m/s^2

Question 18

Average Speed

Answer 18

Average speed tells you what happened over the course of the interval, but not necessarily what happened at any given moment.
Vav = Δd/Δt (Note: there are NO vector signs!!)

Question 19

Instantaneous Speed

Answer 19

Instantaneous speed tells you the speed at a precise moment. It must be calculated with limits (or from graphs).
(Note: this is similar for instantaneous velocity)
Don’t need & won’t be asked about limits!!

Question 20

Average Velocity

Answer 20

Vav = Δd/Δt = (d2 - d1)/Δt (Note: there are vector signs on each except for time!!)

Question 21

Average Acceleration

Answer 21

aav = ΔV/Δt = (v2 - v1)/Δt (Note: there are vector signs on each except for time!!)

Question 22

Uniform Motion

Answer 22

Situations where velocity is constant

Question 23

If velocity is constant, what can we determine about acceleration?

Answer 23

a = ΔV/Δt –> a=0 (Note: there are vector signs on each except for time!!)

Question 24

Describing the motion from looking at a graph: Moving forward/backwards

Answer 24

”+” or “-“ slope

Question 25

Describing the motion from looking at a graph: Moving faster/slower

Answer 25

Steepness of slope

Question 26

Describing the motion from looking at a graph: Instantaneous velocity/speed

Answer 26

slope, | slope |

Question 27

Describing the motion from looking at a graph: Average velocity

Answer 27

Slope of secant

Question 28

Describing the motion from looking at a graph: Displacement for an interval

Answer 28

"rise"

Question 29

Describing the motion from looking at a graph: Total distance for an interval

Answer 29

Δd = | d2 - d1 | + | d3 - d2 | + . . . (Note: there is NO vector sign on Δd, but there is on the rest!!)

Question 30

Describing the motion from looking at a graph: Average speed

Answer 30

Vav = Δd/Δt (Note: there are NO vector signs!!)

Question 31

On a d-t graph, can you find the instantaneous velocity at a turning point? Why or why not?

Answer 31

No! This is because in real life there would be a curve transition not an exact turning point (straight line).

Question 32

What can you summarize about position-time graphs for uniform acceleration?

Answer 32

- The d-t graph is parabolic for uniform acceleration (Note: there is a vector sign on "d") - The parabolic shape opens p for acceleration in the positive direction - The parabolic shape opens down for acceleration in the negative direction

Question 33

Slope of a secant on a position-time graph

Answer 33

A line between 2 points on the graph; it's equal to the average velocity during that time interval.

Question 34

Slope of a tangent on a position-time graph

Answer 34

It's equal to the instantaneous velocity at that instant in time

Question 35

Tangent

Answer 35

The straight line that jut touches the graph at a point

Question 36

5 Equations of Motion

Answer 36

1. V2 = V1 + aΔt (Note: don't forget about the vector signs!!) 2. Δd = [ (V1 + V2) / 2 ] x Δt (Note: don't forget about the vector signs!!) 3. Δd = V1Δt + 1/2aΔt^2 (Note: don't forget about the vector signs!!) 4. Δd = V2Δt - 1/2aΔt^2 (Note: don't forget about the vector signs!!) 5. (V2)^2 = (V1)^2 + 2aΔd (Note: don't worry about putting the vector signs!!)

Question 37

Quadratic Formula

Answer 37

x = [ -b ± sqareroot(b^2 - 4ac) ] / 2a

Question 38

Tail

Answer 38

The beginning of the vector

Question 39

Tip/head

Answer 39

The end of the arrow

Question 40

Projectile motion

Answer 40

A special example of 2D motion. This describes the situation when an object is moving freely under the influence of gravity.