LECTURE #7 - projectile motion

Question 1

what are the four important terms of projectile motion ?

Answer 1

• projectile
• trajectory
• release
• apex

Question 2

what is trajectory ?

Answer 2

fight path of a projectile

Question 3

what is projectile ?

Answer 3

object in free-fall that is affected only by gravity and air resistance

Question 4

what is release ?

Answer 4

when object becomes a project (ex. angle of basketball being thrown)

Question 5

what is apex ?

Answer 5

highest point in trajectory (highest point pleasing ball @ the apex)

Question 6

how many primary purposes in projecting ?

Answer 6

5

Question 7

what are the five primary purposes in projecting ?

Answer 7

• maximize horizontal distance
• maximize vertical height
• maximize accuracy
• maximize accuracy when speed enhances effectiveness
• maximize time in the air

Question 8

what are examples of maximize horizontal distance ?

Answer 8

javelin, discus, shotput

Question 9

what are examples of maximize vertical height ?

Answer 9

high jump, pole vault, etc.

Question 10

what are examples of maximize accuracy ?

Answer 10

golf, basketball and archery

Question 11

what are examples of maximize accuracy when speed enhances effectiveness ?

Answer 11

baseball throw, football toss, etc.

Question 12

what are examples of maximize time in the air ?

Answer 12

gymnastics, diving, etc.

Question 13

how many factors influencing projectile motion are there ?

Answer 13

3

Question 14

what are the 3 factors influencing projectile motion ?

Answer 14

1. relative height of release
2. angle of release
3. velocity of release

Question 15

FILL IN THE BLANK

relative height of release = projectile _______

Answer 15

projectile height

Question 16

FILL IN THE BLANK

angle of release = projection _____

Answer 16

projection angle

Question 17

FILL IN THE BLANK

velocity of release = projectile ________

Answer 17

projectile velocity

Question 18

TRUE OR FALSE

magnitude of the velocity = speed

Answer 18

TRUE

Question 19

TRUE OR FALSE

more projectile height = more fight time

Answer 19

TRUE

Question 20

given a constant projectile velocity & angle : increase or decrease for the following …
__ projectile height → __ flight time → __ horizontal displacement

Answer 20

↑ projectile height → ↑ flight time → ↑ horizontal displacement

Question 21

TRUE OR FALSE (release Ht = landing Ht)

time to apex = time to land & v(y) release = v(y) landing

Answer 21

TRUE

Question 22

TRUE OR FALSE (release Ht > landing Ht)

time to apex < time to land & v(y) release < v(y) landing

Answer 22

TRUE

Question 23

TRUE OR FALSE (release Ht < landing Ht)

time to apex > time to land & v(y) release > v(y) landing

Answer 23

TRUE

Question 24

what is projection angle ?

Answer 24

influences shape of projectile’s trajectory

Question 25

describe the trajectory of projection θ = 90 degrees → ________ trajectory (v(x) = 0

Answer 25

vertical trajectory

Question 26

describe the trajectory of projection θ = 0-90 degrees → ________ trajectory

Answer 26

parabolic trajectory

Question 27

describe the trajectory of projection θ = 0 degrees → latter 1/2 _________ trajectory (v(y) initial = 0

Answer 27

parabolic trajectory

Question 28

what two thing does optimal projection angle depend on ?

Answer 28

depends on goals of performance and projection height

Question 29

define "depends on goals of performance"

Answer 29

maximize vertical displacement and maximize horizontal displacement

Question 30

define "depends on projection height"

Answer 30

- release Ht = landing Ht - release Ht > landing Ht - release Ht < landing Ht

Question 31

give an example of : release Ht = landing Ht

Answer 31

kick a ball for a max horizontal displacement

Question 32

give an example of : release Ht > landing Ht

Answer 32

throw a ball for a max horizontal displacement

Question 33

give an example of : release Ht < landing Ht

Answer 33

throw a ball onto elevated surface

Question 34

what does projectile velocity determine (given a constant projectile angle & height) ?

Answer 34

projectile velocity determines magnitude of vertical and horizontal displacement

Question 35

TRUE OR FALSE velocity is a vector

Answer 35

TRUE

Question 36

TRUE OR FALSE velocity has a horizontal v(x) and vertical v(y) component ?

Answer 36

TRUE

Question 37

TRUE OR FALSE projectile have velocity ?

Answer 37

YES

Question 38

describe vertical component v(y) :

Answer 38

- influences max vertical displacement - constantly changing due to gravity

Question 39

describe horizontal component v(x) :

Answer 39

- influences horizontal displacement (range) - remains constant (assuming minimal air resistance)

Question 40

TRUE OR FALSE magnitude depends on projection angle

Answer 40

TRUE

Question 41

TRUE OR FALSE gravity is always pulling down ?

Answer 41

TRUE

Question 42

do flat angles have smaller/larger horizontal/vertical component ?

Answer 42

flat angles have larger horizontal components

Question 43

do steep angles have smaller/larger horizontal/vertical components ?

Answer 43

larger vertical component

Question 44

between velocity, height and angle of release what is necessarily the most important ?

Answer 44

velocity (can continue to manipulate)