Angular Kinematics

Question 1

Define angular motion.

Answer 1

Movement about a fixed axis of rotation.

Question 2

How is angular position & displacement quantified?

Answer 2

Degrees.
Revelations.
Radians. 1 rad = 57.3°. Full circle = 6.28 rad

Question 3

What is the formula for circumference?

Answer 3

2 pie r

Question 4

Define angular distance.

Answer 4

Sum of angles through which an object moves in passage from the initial and final position (scalar quantity).

Question 5

Define angular displacement.

Answer 5

The magnitude of the difference between the initial and final positions of a rotating object (vector quantity)

Question 6

What is the formula for average angular speed?

Answer 6

Average angular speed = change in angular distance/time

rad.s-1

Question 7

What is the formula for angular velocity?

Answer 7

Average angular velocity = change in angular displacement/time
(rad.s-1)

Question 8

What is angular acceleration?

Answer 8

The rate of change of angular velocity with respect to time.

Question 9

Formula for angular acceleration?

Answer 9

Angular acceleration = change in angular velocity/time

a=dw/dt

Question 10

The angle of TD = 61° and TO = 84° and the phase lasts 0.11s. What is the average angular velocity of the gymnast during this phases?

Answer 10

=209.1 rad.s-1

Question 11

Determine the angular displacement of the shank in radians. (Angle = 48.1°)

Answer 11

-see notes-

Question 12

If the player executed a kick (duration 0.23s) from rest and the angular velocity of the shank at ball impact was 98.7rad.s-1, calculate the average angular acceleration of the shank at ball impact. (Angle = 48.1°)

Answer 12

=429.13 rad.s-2

Question 13

What is the standard SI unit for angular displacement?

Answer 13

Radians

Question 14

What is the formula for arc length(s)?

Answer 14

Arc length = angular displacement x radius of rotation (r)

Question 15

What is the formula for tangential velocity?

Answer 15

tangential velocity(Vt) = angular velocity(w) x radius of rotation(r)

Question 16

A javelin thrower has an arm length of 1.2m and releases the javelin with a linear velocity of 3.1m/s. What is the angular velocity of the throwing arm at release? How could the linear velocity of the javelin be maximised?

Answer 16

-see notes-

Question 17

What is the formula to work out the time taken to complete one revaluation?

Answer 17

T=2 pie r/v or 2 pie/w

Question 18

What is the primary technique used to capture data for sprint performance?

Answer 18

Automatic motion analysis

Question 19

What two key sets of measures can be derived from motion capture analysis?

Answer 19

1. Quantification of performance-related outcomes e.g. step length and rates.
2. Underlying joint mechanic measures e.g. the degree of knee motion utilised as specific step-based events or during the entire phase are examined.