Acceleration

Question 1

if sign of acceleration is same as velocity =

Answer 1

speeding up

Question 2

if sign of acceleration if opposite to velocity =

Answer 2

slowing down

Question 3

angular motion

Answer 3

all parts of a body moves through the same angle but not the same linear displacement

Question 4

angle

Answer 4

a figure formed by 2 lines that intersect at a vertex

Question 5

revolution (rev)

Answer 5

of times about a circle

Question 6

degree

Answer 6

360 in a circle

Question 7

radian (rad)

Answer 7

• ratio of the arc length to the radius of the circle (SI unit)
• 2pi rad in a circle

Question 8

absolute angle

Answer 8

• segment angle

- angular orientation of a body segment with respect to some fixed reference

Question 9

convention

Answer 9

counterclockwise from right horizontal (but can choose other axes too)

Question 10

relative angle

Answer 10

• joint or intersegmental angle
• angle formed between longitudinal axes of body segments
• no consistent convention for measuring relative angles

Question 11

measure of angular kinematics

Answer 11

find the absolute angle of each segment, then find the relative angle of the joint by adding them

Question 12

angular displacement

Answer 12

• difference between initial and final positions of a rotating object

Question 13

counter clockwise (CCW) is \_\_\_\_\_ 
clockwise (CW) is \_\_\_\_\_\_

Answer 13

CCW: positive
CW: negative

Question 14

angular speed is

Answer 14

angular distance covered over a period of time (scalar)

Question 15

angular velocity is

Answer 15

change in angular position over a period of time (vector)

Question 16

tangential velocity =

Answer 16

linear velocity

Question 17

angular to linear velocity

Answer 17

often want to increase linear tangential velocity in order to improve performance

Question 18

angular acceleration

Answer 18

sign of angular acceleration does not indicate direction of rotation