u1: kinematics

Question 1

what happens when a vector is multiplied?

Answer 1

the length changes but direction stays the same

Question 2

what happens when a vector is multiplied by -1?

Answer 2

direction changes by 180: opposite direction

Question 3

adding vectors: A+B

Answer 3

• tail to tip
• resultant: start to finish

Question 4

subtracting vectors: A-B

Answer 4

• tail to tail, resultant: arrow points to initial
• A+(-B): draw B with opposite direction tail to tip, resultant: start to finish

Question 5

what must you do when adding/subtracting vectors in drawings?

Answer 5

include the angle
(extend line of one arrow until it touches and measure angle)

Question 6

formula for resultant displacement using pythagorean theorem

Answer 6

dR = SQRT(d1)^2(d2)^2

Question 7

formula for finding angle using tan inverse

Answer 7

theta = (tan-)(d2/d1)
or opp/adj

Question 8

which directions are typically negative numbers when doing component analysis?

Answer 8

west and south

Question 9

sum of x and y components formula for position vector A

Answer 9

• A = AxX + AyY
• final x and y have hats to signify “units”

Question 10

avg acceleration formula

Answer 10

aavg = (vf-vi)/t

Question 11

what MUST be included in givens when solving 2D displacement Qs

Answer 11

deltadR = deltad1+deltad2

Question 12

what must you include when calculating the magnitude of components

Answer 12

direction

Question 13

where does theta go

Answer 13

between dR and initial vector

Question 14

what is everything relative to

Answer 14

the ground

Question 15

all motion is…

Answer 15

relative

Question 16

V(AB) represents….

Answer 16

A relative to B

Question 17

what is motion dependent on

Answer 17

• the point of view we describe the motion from
• also known as FOR: frame of reference

Question 18

most common frame of reference

Answer 18

earth

Question 19

what do we assume earth is?

Answer 19

• stationary
• it isn’t actually

Question 20

what MUST you include in relative velocity Qs?

Answer 20

• analysis (use chain rule)

Question 21

step one in relative velocity Qs

Answer 21

state variables

Question 22

if you have V(AB), what is V(BA)?

Answer 22

• inverse velocity (direction)
• V(AB) = -V(BA)

Question 23

if a wind is coming from the west, wht direction is it going?

Answer 23

east

Question 24

whats a projectile

Answer 24

any object thts thrown/launched/dropped and moves freely through earth’s gravitational field

Question 25

horizontal velocity is....

Answer 25

constant

Question 26

vertical acceleration is....

Answer 26

constant

Question 27

vertical motion and horizontal motion are...

Answer 27

independent of each other

Question 28

what kind of path results from a horizontal launch

Answer 28

parabolic path

Question 29

horizontal direction

Answer 29

- velocity(x) is constant - V(i)(x) = V(f)(x) - so, we can use: d(x) = V(x)t

Question 30

vertical direction

Answer 30

- acceleration (9.8m/s2 down) - HORIZONTAL LAUNCH: V(i)(y) = 0 - use: dy = v(iy)t + 1/2a(y)t^2 - final velocity: v(f) = v(iy) + a(y)t

Question 31

conditions for projectile motion

Answer 31

1. motion in horizontal and vertical are independent 2. object moving freely in gravitational field 3. object follows a parabolic trajectory 4. motion conditions: - vertical: constant acceleration - horizontal: constant velocity

Question 32

first step in projectile problems

Answer 32

- diagram - +y +x axis/scale

Question 33

how do u do direction for the velocities of projectiles?

Answer 33

degree above/below the horizontal

Question 34

cheat equations for vertical launches when d(y) = 0

Answer 34

t(T) = (2V(i)sintheta)/g d(x)=(V(i)^2sin2theta)/g

Question 35

when launching problem is perfect parabola, how do u find final velocity?

Answer 35

final velocity = initial velocity but opposite direction - bc symmetrical parabola

Question 36

when does uniform circular motion occur

Answer 36

when object moves in circular path at constant magnitude, not direction

Question 37

is there acceleration tangentially in circular motion?

Answer 37

no, because speed is constant

Question 38

where is acceleration i circular motion directed

Answer 38

radially inward and acts to change velocity direction

Question 39

centre-seeking acceleration:

Answer 39

centripetal acceleration

Question 40

a(c) = v^2/r

Answer 40

a(c): instantaneous acceleration v = speed r: radius of circular path (m)

Question 41

T stands for

Answer 41

period (time for one revolution, seconds)

Question 42

frequency

Answer 42

- number of cycles in one second - Hz or s^-1

Question 43

velocity vector in circular motion

Answer 43

- constant in magnitude - directed tangent to the path

Question 44

when solving 2D displacement, wht must u include

Answer 44

dR=d1+d2

Question 45

when solving 2D velocity, wht must u include

Answer 45

v=v2-v1 v2=v+v1 v1=v2-v

Question 46

whats a vector

Answer 46

quantities with magnitude and direction

Question 47

what units do u use in scale diagrams

Answer 47

label as km (or wtv given in question) not cm