Midterm 1 review

Question 1

counter clockwise rotations have a

Answer 1

positive sign

Question 2

clockwise rotations have a

Answer 2

negative sign

Question 3

what is displacement

Answer 3

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

Question 4

how are distance and displacement different

Answer 4

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

Question 5

what does going from a positive to negative displacement mean

Answer 5

the change in position/orientation is a nat negative direction or rotation

Question 6

what is velocity

Answer 6

the rate of change in displacement over a particular interval

Question 7

what does change in direction mean in terms of a velocity vector

Answer 7

a Change in direction is the change in the sign (+ or -) of velocity

Question 8

how are velocity and displacement related

Answer 8

velocity sets rate of displacement

increased velocity = increased displacement over time

decreased velocity = decreased displacement over time

Question 9

what is acceleration

Answer 9

the rate of change in velocity over a time interval

Question 10

how are velocity and acceleration related

Answer 10

sets the change in velocity (signs matter)

Question 11

what happens to velocity when there is no acceleration

Answer 11

velocity is a constant when there is no acceleration

Question 12

when in the air, the following assumption can be made:
acceleration is _____________________ therefore vertical velocity is changing

Answer 12

constant in the vertical direction at -9.81m/s2

Question 13

when in the air, the following assumption can be made:
the projectiles ______ dictates how long the projectile will be in the air

Answer 13

initial velocity

Question 14

when in the air, the following assumption can be made:
acceleration is a ______________________ therefor velocity in the horizontal direction is constant

Answer 14

constant with a value of zero in the horizontal direction

Question 15

if the launch and landing point are equal, the time form launch to apex is equal to

Answer 15

the time from apex to landing

Question 16

displacement vs. time graphs
what does a negative displacement value mean ?

Answer 16

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

Question 17

displacement vs. time graphs
what does the slope represent

Answer 17

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

Question 18

displacement vs. time graphs
when would we see a change in direction

Answer 18

when the slope is equal to zero

Question 19

displacement vs. time graphs
when would the object be undergoing a constant rate of acceleration

Answer 19

when the slope is constant since this would indicate velocity is a constant

Question 20

determining joint position
HIP

Answer 20

a positive angle indicates a flexed position, 0 indicates a neutral position, a negative angle indicates and extended position

Question 21

determining joint position
KNEE

Answer 21

a positive angle indicates a flexed position, 0 indicates an extended position and negative indicates a hyperextended position

Question 22

determining joint position
ANKLE

Answer 22

a positive angle indicates a dorsiflexed position, 0 indicates a neutral position and negative indicates a plantar flexed position

Question 23

joint angle vs. time

Answer 23

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