2.4. Motion

Question 1

motion definition

Answer 1

change of location or position of an object with respect to time

Question 2

how do you analyse motion

Answer 2

describe the position of a body and the time between positions

Question 3

what is a body

Answer 3

it can be inanimate - eg sporting equipment
or animate - human body or body parts

Question 4

how do you create motion

Answer 4

by applying a force

internally - by muscle contraction
externally - gravity, resistance, ground reaction, friction

Question 5

linear motion definition

Answer 5

straight line movement of an object or body

occurs when all parts of the body or object move in the same direction at the same speed when acted upon by a force

eg 100m swimmer in a straight line

Question 6

mass definition

Answer 6

quantity of matter (kg)

Question 7

weight definition

Answer 7

force of a given mass due to gravity (N)

Question 8

acceleration definition

Answer 8

rate which velocity changes with respect to time (m/s²)

Question 9

displacement definition

Answer 9

shortest distance between the start point and end point (m)

Question 10

distance definition

Answer 10

total length of the path an object travels (m)

Question 11

velocity definition

Answer 11

rate an object changes its position (m/s)

Question 12

speed definition

Answer 12

rate a body moves from one location to another (m/s)

Question 13

momentum definition

Answer 13

quantity of motion

Question 14

scalar quantity

Answer 14

those with only magnitude

mass, speed, distance

Question 15

vector quantity

Answer 15

those with magnitude and direction

displacement, velocity, weight, acceleration

Question 16

acceleration equations

Answer 16

final velocity - initial velocity / time (V2 - V1 / t)

OR

force / mass

Question 17

speed, distance, time triangle equations

Answer 17

speed = distance / time (m/s)
distance = speed x time (m)
time = distance / speed (s)

Question 18

displacement, velocity, time triangle equations

Answer 18

displacement = velocity x time (m)
velocity = displacement / time (m/s)
time = displacement / velocity (s)

using a velocity-time graph - displacement = area under graph

Question 19

angular motion definition

Answer 19

rotation or circular movement of a body around an axis or point

Question 20

axis of rotation definition

Answer 20

imaginary line which rotation occurs around

Question 21

angular momentum euqation

Answer 21

the quantity of rotation

angular momentum = angular velocity x moment of inertia

when an athlete rotates, angular remains remains constant

Question 22

moment of inertia definition

Answer 22

the resistance of a body to change state when rotating

how the performer distributes their mass around their axis of rotation

when MOI increases, angular velocity decreases
when MOI decreases, angular velocity increases

Question 23

angular displacement definition

Answer 23

the change in angular position of a body or body part

• measured in degrees or radians, represents the angle through which a segment has rotated
• the smallest angle between starting and finishing position

Question 24

angular displacement equation triangle

Answer 24

angular displacement = angular velocity x time (RAD/°)
angular velocity = angular displacement / time (RAD/°)
time = angular displacement / angular velocity

Question 25

angular acceleration definition

Answer 25

rate at which angular velocity changes over time

Question 26

angular acceleration euqation

Answer 26

angular acceleration = angular velocity 2 - angular velocity 1 / time AV2 - AV1 / t (RAD/s) or (°/s)

Question 27

what factors does moment of inertia depend on

Answer 27

- mass of object - larger mass = larger moment of inertia - distribution of mass from axis - larger distribution/further away = larger moment of inertia