LECTURE #6 - linear kinematics (2)

Question 1

what are kinematics ?

Answer 1

describes ,motion in regards to the position, velocity, and acceleration of object without considering the forces causing motion

Question 2

what is distance ?

Answer 2

length of a path followed by object from initial to final position

Question 3

TRUE OR FALSE

distance is necessarily a straight line

Answer 3

FALSE

not necessarily a straight line

Question 4

what is scalar quantity ?

Answer 4

one magnitude

Question 5

length of path is described by what term ?

Answer 5

distance

Question 6

what is displacement ?

Answer 6

straight line distance in a specific direction from initial to final position

Question 7

“as the crow flies” is used for what term ?

Answer 7

displacement

Question 8

what is the formula for displacement ?

Answer 8

displacement = position (final) - position (initial)

Question 9

TRUE OR FALSE

distance and displacement = the same thing ?

Answer 9

FALSE

distance doesn’t = displacement

Question 10

which line in a graph is displacement ?

Answer 10

the straight line from the initial to the final

Question 11

TRUE OR FALE

think of resultant as the displacement

Answer 11

TRUE

Question 12

how do we calculate displacement :

Answer 12

x1,y1 & x2,y2 is resultant
- use SOHCAHTOA (in this case tan) and solve the missing sides
0 used pythagorean theorem

Question 13

what sport did we discuss displacement for ?

Answer 13

tennis

Question 14

describe some points based of the tennis video :

Answer 14

• no more line judges
• evolution in business and the sport of tennis
• cost expensive
• clear application that influences tennis

Question 15

what is speed ?

Answer 15

rate of motion

Question 16

how to calculate speed ?

Answer 16

Δ displacement / Δ time

Question 17

TRUE OR FALSE

scalar quantity is magnitude only

Answer 17

TRUE

Question 18

what term is used for how long it takes to accomplish a rate of motion/speed/movement ?

Answer 18

time

Question 19

what is velocity ?

Answer 19

displacement of an object over time

Question 20

what is the formula for velocity (v) ?

Answer 20

v = Δ displacement / Δ time

Question 21

TRUE OR FALSE

the friction of velocity (v) is negative or positive

Answer 21

TRUE

Question 22

TRUE OR FALSE

direction of motion influences velocity direction

Answer 22

TRUE

Question 23

what formula is used to find the resultant ?

Answer 23

pythagorean theory

Question 24

what are the two methods of instantaneous velocity ?

Answer 24

• central difference method
• tangent

Question 25

what does it mean when velocity is positive ?

Answer 25

- going upwards - gain in position

Question 26

what does it mean when velocity is straight line ?

Answer 26

- vertical velocity is 0 - constant

Question 27

what does it mean when velocity is negative ?

Answer 27

- going downwards - lose in position

Question 28

TRUE OR FALSE rate of change in velocity is a vector quantity (acceleration)

Answer 28

TRUE

Question 29

TRUE OR FALSE acceleration occurs if velocity magnitude or direction changes

Answer 29

TRUE

Question 30

what are the three types of acceleration ?

Answer 30

positive negative and zero

Question 31

what does positive acceleration mean ?

Answer 31

gaining velocity

Question 32

what does negative acceleration mean ?

Answer 32

losing velocity

Question 33

what does zero acceleration mean ?

Answer 33

means @ that point you're at a constant role (it's remaining constant)

Question 34

is someone described as being "quick" or having "good acceleration" the same as being fast ?

Answer 34

- No ! - acceleration describes a persons ability to change speed or direction (not top speed)

Question 35

is a 400m runner that is running at a constant speed around a track accelerating ?

Answer 35

yes & no on the straights we are not accelerating because there is no change in direction, but around the curved we are changing directions therefore ac celebration has occurred

Question 36

average vs instantaneous ... what is average ?

Answer 36

- value over an interval or time - do not represent max values

Question 37

average vs instantaneous ... what is instantaneous ?

Answer 37

- value at a given moment in time - may represent max values - approach instantaneous measures with small time intervals

Question 38

what odes magnitude of instantaneous velocity = ?

Answer 38

instantaneous see

Question 39

when do we usually see max velocity ?

Answer 39

@ around 2/3

Question 40

when do we see max acceleration ?

Answer 40

@ beginning

Question 41

what is the formula for acceleration ?

Answer 41

velocity / time