Biomechanics Projectile Kinematics

Human bodies can be identified as projectiles? T/F

true

What does a projectile refer to?

An object moving in the air

What forces are projectiles subject to?

gravity and air resistance

Which of the two components (vertical or horizontal) are influenced by gravity?

vertical

What is the acceleration of gravity?

-9.81 m/s²

What shape of movement does gravity cause on a projectile?

a parabolic curve that is symmetric without air resistance

What are the three factors that influence the trajectory of a projectile?

projection angle, projection velocity, and projection height

What is the projection angle?

the angle that the projectile is released at

What direction is a 90 degree projection angle?

up and down

What does a 0 degree release angle do to a projectile?

it causes the trajectory to only travel down

What is the optimum degree for maximum distance of a projectile?

42 - 45 degrees

Why do shot put athletes throw at around 37 degrees instead of 45 degrees?

due to physiological limitations and greater muscle recruitment at lower angles

What is projection velocity?

the velocity of a projectile at its release point

What does projection velocity determine?

the length and range of trajectory

What is the resultant velocity?

the vector sum of the horizontal and vertical velocities

Gravity affects the vertical velocity during a projectile’s flight? T/F

true

When is positive vertical velocity the highest?

at the release point

When is vertical velocity equal to 0?

at the apex of the trajectory

What is projection height?

the height of the projectile at its release point

Why do long jumpers jump at an angle of 17-32 degrees?

it may not be possible to generate the vertical velocity needed without sacrificing horizontal velocity

What can you find using Galileo’s laws of constant acceleration?

velocity, height, or time

What determines how much time a projectile spends in the air?

projection height and vertical velocity

If take off position is equal to landing height, then time up equals what?

time down

A greater time up than time down means the projectile impacts higher or lower than the starting height?

higher

A greater time down than time up means the projectile impacts higher or lower than the starting height?

lower

The total time travelled of a projectile is what plus what?

time up plus time down