angular motion

Question 1

angular motion

Answer 1

movement around a fixed point

Question 2

transverse axis and eg

Answer 2

side to side e.g. somersault

Question 3

sagittal axis and eg

Answer 3

front to back e.g. cartwheel

Question 4

longitudinal axis and eg

Answer 4

top to bottom e.g. spin in ice skating

Question 5

torque and formula

Answer 5

rotational consequence of a force

= force x perpendicular distance from fulcrum

Question 6

newtons first law or angular motion

Answer 6

rotating body will continue to turn about its axis with constant angular momentum unless an external rotational force (torque) is acted upon it

Question 7

newtons second law of angular motion

Answer 7

the rate of change of angular momentum of a body is proportional to the force (torque) causing it and the change that takes place in the direction in which the force (torque) acts

Question 8

newtons third law of angular motion

Answer 8

when a force is applied by one to another, the 2nd body will exert an equal and opposite force on another body

Question 9

angular displacement

Answer 9

smallest change in angle between start and finish point of a rotation

Question 10

angular velocity and formula

Answer 10

rate of change of angular displacement

= angular displacement (rad) / time taken(s)

Question 11

angular acceleration and formula

Answer 11

rate of change of angular velocity

= change in angular velocity(rad) / time taken (s)

Question 12

radian to degrees

Answer 12

1 radian = 57.3 degrees

Question 13

moment of inertia

Answer 13

resistance of a body to angular motion

- applied to start of rotation when body will resist AM

Question 14

moment of inertia depends on:

Answer 14

1. mass of body/object - greater the mass the greater the resistance to change = increased MOI
2. distribution of mass from the axis of rotation - increased distance from axis of rotation will increase MOI

Question 15

angular momentum and formula

Answer 15

quantity of rotation a body possesses

momentum of inertia x angular velocity

Question 16

characteristics of angular momentum

Answer 16

• stays constant unless an external force is acted upon it
• occurs during flight/ice/snow
  e. g. diver AM is constant till he hits the water or changes body position

Question 17

conservation of angular momentum

Answer 17

only a figure skater can manipulate moment of inertia to increase or decrease speed of spin

• increased distance from axis of rotation = large MOI and angular momentum so rotation is slow