3 - Linear Kinematics

Question 1

What are the forms of motion and describe them?

Answer 1

Translation - all parts of the body move through the same distance in the same time

Rotation - all parts of the body move through the same angle at the same time

Question 2

What are the two types of linear motion?

Answer 2

Rectilinear - translation occurs along the straight line

Curvilinear - translation occurs along the curved line

Question 3

What are the two approaches in biomechanics?

Answer 3

Kinematics - description of motion

Kinetics - causes of motion

Question 4

What is kinematics?

Answer 4

How far the body has moved, how fast it moves and how consistently it moves

Question 5

What is the linear kinematics?

Answer 5

Describes the motion of the bodies that are undergoing translation motion through time

Question 6

What is the centre of mass?

Answer 6

The point around which the mass of a body is equally distributed and through which the line of action of the weight force can be assumed to act

Question 7

What is the location of the centre of mass?

Answer 7

When a body is in a fixed position with the line of gravity, the line is balanced and stable

Question 8

How can you increase balance?

Answer 8

Lowering the centre of mass

Move lower limbs further apart

Question 9

The location of the centre of mass can be changed by doing what?

Answer 9

change in body shape

movement of limbs

Question 10

Why is the centre of mass important?

Answer 10

Determines the way the body responds to external forces

Question 11

What is a scalar?

Answer 11

Described in terms of magnitude

Question 12

What is a vector?

Answer 12

described in terms of magnitude and direction

Question 13

What is a position?

Answer 13

Location in space relative to a reference

Question 14

What is trajectory?

Answer 14

The path followed by the object in motion

Question 15

What is distance and displacement?

Answer 15

Distance - length of trajectory

Displacement - change in position

Question 16

What three things does a vector have?

Answer 16

Magnitude
Direction
Point fo origin

Question 17

A vector can be represented graphically by?

Answer 17

Line of action

Question 18

How can magnitude and direction be quantified?

Answer 18

Pythagaroeam theorem

Trigonometry

Question 19

What is a distance-time graph?

Answer 19

Gradient = speed
Straight line means constant speed
Steeper the line, the greater the speed

Question 20

What is a velocity-time graph?

Answer 20

Gradient = acceleration

Question 21

What is velocity?

Answer 21

Speed in a given direction

Question 22

What is the first derivative of displacement?

Answer 22

velocity

Question 23

What is the second derivative of displacement?

Answer 23

acceleration

Question 24

What does the gradient of a chord show on a displacement-time graph?

Answer 24

The gradient of a chord between the 2 points gives the average velocity over that time interval

Question 25

How can running velocity be increased?

Answer 25

It can be increased by stride/step length or step/stride frequency

Question 26

What are the common parameters of running?

Answer 26

stride/step length
stride/step frequency
velocity

Question 27

How do we find the instantaneous velocity?

Answer 27

At a particular instant in time, the gradient of the tangent gives the instantaneous velocity

Question 28

What is a resultant velocity?

Answer 28

the vector describing the net effect of all of the vectors the body is experiencing

Question 29

What does uniform accelerated motion mean?

Answer 29

When a body experiences the same acceleration throughout an interval in time its acceleration is constant