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Flashcards in Projectile Motion Deck (14)
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Object in free-fall that is affected only by gravity and air resistance



Flight path of a projectile



When object becomes a projectile



Highest point of trajectory


Primary Purposes in Projecting

Maximize horizontal distance (javelin, discus, shotput, long jump)

Maximize vertical height (High jump, pole vault)

Maximize Accuracy (archery, golf)

Maximize Accuracy when speed enhances effectiveness (football pass, baseball throw, tennis shot)

Maximize time in the air (gymnastics, figure skating, diving)


Factors Influencing Projectile Motion

1. Relative height of release (projectile height)
What height was projectile released?
What height did projectile land?

2. Angle of release (projection angle)

3. .Velocity of release (projectile velocity)
Magnitude of the velocity (= speed): how fast?


Projectile Height

Given a constant projectile velocity & angle:
↑ projectile height → ↑ flight time → ↑ horizontal displacement

3 ways projectile height influences projectile motion


Projection Angle

Influences shape of projectile’s trajectory
Projection θ = 90° → Vertical trajectory
vx = 0

Projection θ between 0-90° → Parabolic trajectory

Projection θ = 0° → latter ½ of parabolic trajectory
vy initial = 0


Optimal Projection Angle?

Depends on goals of performance
Maximize vertical displacement → steep projection θ
Exp: high jump, pole vault
Maximize horizontal displacement → small projection θ
Exp: long jump, triple jump

Depends on projection height
Release Ht = Landing Ht → Optimal projection θ = 45 °
Exp: kick a ball for max horizontal displacement
Release Ht > Landing Ht → Optimal projection θ < 45 °
Exp: throw a ball for max horizontal displacement
Release Ht < Landing Ht → Optimal projection θ > 45 °
Exp: throw a ball onto elevated surface


Projectile Velocity

Given a constant projectile angle & height:
Projectile velocity determines magnitude of vertical & horizontal displacement
velocity is a vector

velocity has a horizontal (vx)
and vertical (vy) component


Projectile Vertical Component

Vertical Component (vy)
Influences max vertical displacement (apex)
Constantly changing due to gravity


Projectile Horizontal Component

Horizontal Component (vx)
Influences horizontal displacement (range)
Remains constant (assuming minimal air resistance)


Importance of Velocity, Angle, and Height of Release

Projectile Velocity: most important
↑ vx → ↑ horizontal displacement (range)
↑ vy → ↑ time up & ↑ time down → ↑ total flight time

Projectile Height
↑ total flight time
↑ total flight time → ↑ horizontal displacement (range)
vx and vy remain same

Projectile Angle
Affects ratio of vx & vy
Minimal effect since ↑ in one are offset by ↓ in the other.


Analyzing Projectile Motion

Equations of constant acceleration
Typically, equations are used to describe either horizontal or vertical motion