Linear Kinematics

Question 1

Kinematics can be defined as what?

Answer 1

The area of biomechanics dealing with the description of the spatial & temporal components of motion.

Question 2

What are the types of motion?

Answer 2

• Linear (transitional) - straight-line motion
• Rotational
• Curvillinear motion - translation along a curved path

Question 3

How do you define a performers position? And describe a reference system.

Answer 3

Define performers position using a reference system.
Reference system:
-Cartesian co-ordinate system.
-Two or three dimensional

Question 4

What motion can a 2D reference system describe?

Answer 4

Planar motion

Question 5

What does x axis = in the reference system?

Answer 5

Media-lateral

Question 6

What does the y axis =?

Answer 6

Antero-posterior

Question 7

What does the z axis =?

Answer 7

Vertical

Question 8

Define a scalar quantity and give an example.

Answer 8

Quantities described fully buy their amount or magnitude.

E.g. Mass, distance, volume

Question 9

Define vectors and give an example.

Answer 9

Quantities that cannot be completely described by magnitude alone.
Described by both magnitude & direction.
E.g. Velocity

Question 10

What events does temporal analysis describe?

Answer 10

• Running time or performance.
• Duration of swing phase in place kicking.
• Temporal analysis allows all other kinematic variables to be determined e.g. velocity and acceleration.

Question 11

Define displacement.

Answer 11

• a vector quantity

- measured in a straight line from position to position

Question 12

Define distance.

Answer 12

• a scalar quantity

- may or may not be in a straight line

Question 13

What does speed describe?

Answer 13

Quantifies the Tate at which movement occurs.

Question 14

What does velocity describe?

Answer 14

Quantifies the rate at which movement occurs, incorporating time into distance & displacement measures.

Question 15

What is the formula for speed?

Answer 15

Speed=distance/time

Question 16

What is the formula for velocity?

Answer 16

Velocity=displacement/time

Question 17

What is the unit measure for speed and velocity?

Answer 17

m/s

Question 18

What is the unit measure for acceleration?

Answer 18

m/s/s

Question 19

What is acceleration?

Answer 19

The rate of change of velocity with respect to time.

Question 20

What quantity is acceleration?

Answer 20

Victory quantity

Question 21

What is the formula for acceleration?

Answer 21

Acceleration=change in velocity/time

Question 22

An athlete running 100m increases his velocity from 0-10m/s in3.8s. What’s his average acceleration?

Answer 22

2.63m/s/s

Question 23

An athlete decreases his velocity from 10 to 9m/s in the final 2.7s of the race. What is his average acceleration?

Answer 23

0.37m/s

Question 24

What do equations of motion describe?

Answer 24

Describe the behaviour of a moving system in relation to time.

Question 25

A diver steps off a diving board 3m above the water. What velocity will he reach the water with?

Answer 25

-look for notes-

Question 26

A cyclist isn’t ravelling at 20m/s in the peloton. In order to attempt a breakaway he accelerates at 4m/s/s for 5s. How far does he travel in this time? If the velocity remains constant, what is his lead?

Answer 26

-see notes-

Question 27

During a race a 100m sprinter accelerates by 0.87m/s/s for a duration of 2.1s. Their velocity at the end of this time is 5.64m/s. What was their initial velocity?

Answer 27

7.47m/s

Question 28

What is the formula to work out initial velocity?

Answer 28

u=v+at

Question 29

What is the formula to work out displacement when deriving the equations?

Answer 29

s=0.5(u+v)t

Question 30

Define a step.

Answer 30

Touchdown of one foot to next touchdown of the opposite foot.

Question 31

Define step length.

Answer 31

Displacement covered in one step

Question 32

Define step frequency.

Answer 32

Rate of stepping/

No.step/s

Question 33

Define step velocity.

Answer 33

Step length x step frequency