Midterm 1 review Flashcards
(23 cards)
counter clockwise rotations have a
positive sign
clockwise rotations have a
negative sign
what is displacement
a vector quantity that describes change in an objects position or a segments rotation from an initial location or angle to a final location or angle
how are distance and displacement different
distance reflects the total length travelled or total rotation without respect to direction of movement or rotation
if an object moves in a straight line or rotated in one direction, distance and displacement will be equal
distance is always greater than or equal to displacement
what does going from a positive to negative displacement mean
the change in position/orientation is a nat negative direction or rotation
what is velocity
the rate of change in displacement over a particular interval
what does change in direction mean in terms of a velocity vector
a Change in direction is the change in the sign (+ or -) of velocity
how are velocity and displacement related
velocity sets rate of displacement
increased velocity = increased displacement over time
decreased velocity = decreased displacement over time
what is acceleration
the rate of change in velocity over a time interval
how are velocity and acceleration related
sets the change in velocity (signs matter)
what happens to velocity when there is no acceleration
velocity is a constant when there is no acceleration
when in the air, the following assumption can be made:
acceleration is _____________________ therefore vertical velocity is changing
constant in the vertical direction at -9.81m/s2
when in the air, the following assumption can be made:
the projectiles ______ dictates how long the projectile will be in the air
initial velocity
when in the air, the following assumption can be made:
acceleration is a ______________________ therefor velocity in the horizontal direction is constant
constant with a value of zero in the horizontal direction
if the launch and landing point are equal, the time form launch to apex is equal to
the time from apex to landing
displacement vs. time graphs
what does a negative displacement value mean ?
the object or segment has moved or rotated in a net negative direction. this doe snot mean that the object or is currently moving or rotating in a negative direction
displacement vs. time graphs
what does the slope represent
the slope (rise/run) represents velocity (displacement/time)
the direction (+/-) of the slope indicates the direction of movement or rotation
the steepness indicates the magnitude of velocity
displacement vs. time graphs
when would we see a change in direction
when the slope is equal to zero
displacement vs. time graphs
when would the object be undergoing a constant rate of acceleration
when the slope is constant since this would indicate velocity is a constant
determining joint position
HIP
a positive angle indicates a flexed position, 0 indicates a neutral position, a negative angle indicates and extended position
determining joint position
KNEE
a positive angle indicates a flexed position, 0 indicates an extended position and negative indicates a hyperextended position
determining joint position
ANKLE
a positive angle indicates a dorsiflexed position, 0 indicates a neutral position and negative indicates a plantar flexed position
joint angle vs. time
the direction of the slope (+/-) determines the direction of rotation
a positive slope indicates a counterclockwise rotation. this would indicates hip and knee are undergoing flexion or the ankle is undergoing dorsiflexion
a negative slope indicates clockwise rotation. This would indicate the hip and knee are undergoing extension or the ankle is undergoing plantarflexion
