Projectile Motion

http://www.youtube.com/watch?v

=-uUsUaPJUc0

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Projectile motion

Vertical motion is affected by gravity –

Horizontal motion is affected by friction –

Vertical component

Horizontal component

it is continually decreasing

which can be negligible

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Variations in vertical and horizontal components

This causes the observed parabolic flight and affects the motion components as follows:

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Projectile motion

Factors affecting distance travelled:• • •

Speed of release Height of release Angle of release

Angle of release The optimum angle of release a a

projectile depends upon the relative heights of release and landing

RH = LH optimum angle is 45 deg RH > LH optimum angle is less than 45 deg RH < LH optimum angle is greater then 45

degrees

Examples of these?

Flight Paths Parabolic

Air resistance negligible follows parabolic or symmetrical flight path

Distorted Air resistance is great, projectile veers away

from normal flight path to asymmetrical or distorted flight path

Sporting examples?

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Impulse

Measured during – force

platforms on track Displayed as

Force x time

sprinting

Force x time graph

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timeforce

negative

positive• Impulse = force x time

• shown as area under graph

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Impulse is mainly concerned with

Involves Two parts

single events – a footfall

horizontal forces onlyto a footfall

landing – negative horizontal forces

Push-off – positive horizontal forces

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Typically

timeforce

neg

pos

Landing - negative impulse

Push-off - positive impulse

Net impulse is difference between positive and negative impulses

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Typically

timeforce

neg

pos

Small negative impulse

Large positive impulse

Net impulse is positive – performer is accelerating

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Typically

timeforce

neg

pos

Large negative impulse

Small positive impulse

Net impulse is negative – performer is decelerating