Biomechanics - Kinematic Angular Concepts (Unit 3 AOS 1 Terms)

Question 1

What are the angular motions?

angular

Answer 1

Angular Distance
Angular Displacement
Angular Speed
Angular Velocity
Angular Acceleration

Question 2

angular distance (size and direction) def and example

angular

Answer 2

angular distance covered by a rotating body is the sum of all the angular changes the body undergoes.

For a gymnast performing 1.5 giant circles on the high bar, they have covered 360 degrees and then another 180 degrees. Total angular distance is 540 degrees.

Question 3

angular displacement (size and direction) def and example

angular

Answer 3

the difference between the initial and final angular position of the object.

Using the the gymnast example the angular displacement is 180 degrees - a gymnast performed 1.5 giant circles on the high bar, they have covered 360 degrees and then another 180 degrees.

Question 4

angular speed def and example

angular

Answer 4

the angular distance covered divided by the time taken to complete the motion. (measured in degrees per second).

Speed of rotation is important in sport such as diving, gymnastics and dancing, where athletes need to complete rotations during limited flight time.

Question 5

angular velocity and example

angular

Answer 5

the rate of change of the angular displacement of the body over time. (measured in degrees per second)

Angular velocities increase with the difficulty of the skill being performed. The angular velocity required to complete a single rotation is not as great as the angular velocity required to complete a triple rotation.

Question 6

angular speed question

Eg) What would the angular speed of the gymnast be if they took 3 seconds to complete 1.5 giant circles?

angular

Answer 6

Answer: 180 degrees per second

Question 7

angular velocity question

Eg) What would the angular velocity of the gymnast be if they took 3 seconds to complete 1.5 giant circles?

angular

Answer 7

Answer: 60 degrees per second

Question 8

Angular acceleration def and other information

angular

Answer 8

the rate of change of angular velocity, or how quickly a body changes in its angular position.

Angular acceleration can be positive, negative or zero.

It can be changed by changing the size or direction of the acceleration.

Angular acceleration equal to 0 means that angular acceleration is constant.

The unit of measurement is degrees per second squared

Question 9

Projectile motion def and examples

angular

Answer 9

the motion that any object or body possesses when released into the air
A projectile is influenced by air resistance and gravity.

Examples of projectiles include:
- Equipment such as balls,
shuttlecocks, arrows, javelins, discuses etc.

• Athletes completing actions such as long jumping, vaulting, diving

Question 10

Air resistance ang gravity and examples

Angular

Answer 10

Air resistance is a force working against the horizontal motion of a projectile, while gravity is a force working against vertical motion

Long jump requires the athlete to maximise the horizontal distance, whereas high jump requires the athletes to maximise the vertical distance.

Question 11

Factors affecting the path of a projectile

Answer 11

Angle of release
Speed of release
Height of release

These factors can be manipulated to achieve a particular performance outcome, such as maximising distance, maximising height, or maximising or minimising flight time.

Question 12

Angle of release - def

factor effecting projectile motion

angular

Answer 12

angle at which an object is released into the air.
This angle will determine the flight path of the projectile….the horizontal distance covered.

Question 13

DO I NEED TO KNOW THIS?

there are 3 shapes that a flight path can form
angle of release

factor effecting projectile motion

angular

Answer 13

there are 3 shapes that a flight path can form
1. Purely vertical: when object/body goes up and back down at 90° (volleyball block)

2. Parabolic: when angle is between 0° and 90° (pole vault, long jump)

3/ Half parabola: when angle is 0° or less (lawn bowls)

Question 14

45 degrees
Angle of Release

factor effecting projectile motion

angular

Answer 14

Provided the height of release is approximately equal to the landing height, an angle of release of approximately 45° will maximise horizontal distance.

Only important when going maximal distance

Question 15

0-90 degrees and below 0 degrees
angle of release

factor effecting projectile motion

angular

Answer 15

A projectile is usually released at an angle between 0° and 90°.

However, there are examples where an individual aims to minimise flight time and they release a projectile below horizontal (that is, an angle less than 0°).
The angle of release is measured through the centre of gravity of the object.

Question 16

how to decrease and increase maxiumum height of release
angle of release

factor effecting projectile motion

angular

Answer 16

To decrease the maximum height of the trajectory and flight time of a projectile, a smaller angle of release is required.

To increase the maximum height of the trajectory and flight time of a projectile, a larger angle of release is required.

Question 17

Speed of release - def and the greater…

factor effecting projectile motion

angular

Answer 17

the initial velocity of the proectile when it is released into the air??? - is this right???

The distance a projectile travels is a product of horizontal velocity and flight time (flight time is influenced by the height of release and vertical velocity at release).

The greater the force applied, the greater the velocity at release and the further the projectile will go. Remember Force Summation - more body parts=more speed

Question 18

Height of release

factor effecting projectile motion

angular

Answer 18

If the speed and angle of release are kept constant, changing the height of release will affect the horizontal distance the projectile travels.

If the height that the projectile is being released from is higher than the landing position (positive height of release), the projectile will naturally travel further horizontally (assuming speed and angle of release are kept the same).

Therefore, it might be appropriate to reduce the angle of release if the intended landing position remains the same

If the height that the projectile is being released from is lower than the landing position (negative height of release), the projectile will naturally travel less distance horizontally (assuming speed and angle of release are kept the same). Therefore, it might be appropriate to increase the angle of release if the intended landing position remains the same

Question 19

netball goal - height of release is below finishing point

projectile motion

Answer 19

Performance outcome required is to shoot the ball over the defender to reach the ring.

Projectile is the ball being shot by the goal attack.

Height of release of the ball is below the relevant finishing point (the ring).

As the goal attack appears to be quite close to the ring, the horizontal speed of release does not need to be as great as the vertical speed of release that is needed to clear the defender and reach the ring.

A larger angle of release is needed to clear the defender.

Question 20

kicking a soccer ball for distance - height of release os similar to its landing position

projectile motion example

Answer 20

Performance outcome required is to kick the ball for maximal horizontal distance.

Projectile is the ball being kicked by the player.

Height of release of the ball is similar to the landing point.

Given the aim is to achieve maximal horizontal distance, the horizontal and vertical speed of release needs to be similar (achieving a parabolic flight path).

The angle of release required is approximately 45°.

Question 21

Bowling a cricket ballv - height of release is above landing point

projectile motion example

Answer 21

Performance outcome required is to land the ball on a particular spot on the pitch, just before it reaches the batter.

Projectile is the ball being bowled by the player.

Height of release of the ball is above the landing point.

If the spot aimed for is close to the batter, there will be a greater horizontal speed of release. If the bowler wishes to achieve greater bounce, the vertical speed of release would be increased.

A small angle of release is required. The angle of release is likely below horizontal (that is, less than 0°).

The performance advantage of a taller bowler is an increased height of release. If bowling with the same speed of release as a shorter bowler, the taller bowler can reduce the angle of release to hit the same spot on the pitch. This will increase the bounce the ball has after hitting the pitch