Biomechanics

Question 1

What are Newton’s three laws in order?

Answer 1

1. Inertia
2. Acceleration
3. Action and reaction

Question 2

Describe the law inertia.

Answer 2

objects in motion to stay in motion and objects at rest to stay at rest, unless a force causes its speed or direction to change. (Eg. When the bus stops suddenly, people fall forward)

Question 3

Describe the law of acceleration

Answer 3

When a force acts on an object, the acceleration that takes place depends on the amount of force applied. (Eg. hitting the gas or the brakes)

Question 4

Describe the law of action and reaction

Answer 4

For every action, there is an equal and opposite reaction, This means that when an object exerts a force on a second object, the second object must also exert an equal-sized force back onto the first object in the opposite direction. (Eg. when you push on a box, the box pushes back on you.)

Question 5

What are the three types of motion?

Answer 5

Linear, angular and general motion.

Question 6

What is force?

Answer 6

Forces can be internal, the force created by muscular contractions. Forces can be external, also know as resistive forces.

Question 7

What forces may impact on an object?

Answer 7

-Friction
-Fluid resistance
-Drag
-Gravity

Question 8

What is friction?

Answer 8

Is the force that opposes movement when two surfaces move across each other (wax on a surfboard).

Question 9

Linear motion

Answer 9

Object and its mass move in the same direction, in a straight line.

Question 10

Angular motion

Answer 10

When the body or an object turns about an axis of rotation.

Question 11

General motion

Answer 11

A combination of both linear & angular motion. (Riding a bike, the bike moves in a linear direction but the pedals move in angular motion around an axis).

Question 12

Principles of motion

Answer 12

-Linear motion
-Angular motion
-General motion
-Magnus Effect

Question 13

Difference between speed and velocity?

Answer 13

Speed refers to an object’s change in distance with respect to time, whereas velocity refers to an object’s change in displacement with respect to time.

Question 14

What is momentum?

Answer 14

Momentum is the product of the mass and velocity of an object.

Question 15

What is force summation?

Answer 15

The combination of forces produced by different parts of the human body.

Question 16

What is projectile motion?

Answer 16

The movement of an object through the air is known as projectile motion. The path of a projectile is called its trajectory. (Eg. bullet shot from a gun)

Question 17

What four factors affect projectile motion?

Answer 17

-Angle of release
-Height of release
-Speed of release
-Air resistance

Question 18

What is the magnus effect?

Answer 18

The Magnus effect explains the
deviation of flight paths of balls
with spin. A spinning object moving through a fluid moves away from its straight path because of pressure differences that develop in the air.

Question 19

What is topspin?

Answer 19

Tends to shorten the flight of the ball, which dips sharply at the end of its flight. (Eg. A tennis serve)

Question 20

What is backspin?

Answer 20

Tends to shortens the flight of the ball, which falls more slowly at the end of the flight. (Eg. Drop punt in footy)

Question 21

What is sidespin?

Answer 21

Makes the ball curve left or right in the direction of the spin. (Eg. Baseball curveball.)

Question 22

What is force summation influenced by?

Answer 22

-number of body parts used
-order and timing of the movement
-force and velocity generated
-way in which the body is stabilised and balanced

Question 23

What is balance?

Answer 23

Balance refers to the ability to control the body when you are not moving.

Question 24

What is stability?

Answer 24

Stability refers to the ability to control the body when you are moving.

Question 25

What are the four factors affecting balance and stability?

Answer 25

-the mass
-the base of support
-the centre of gravity
-the line of gravity

Question 26

Base of support

Answer 26

The base of support is the area around the outside edge of your body in contact with the ground/surface

Question 27

Centre of gravity

Answer 27

The centre of gravity is the average location of the weight of an object.

Question 28

Line of gravity

Answer 28

An imaginary vertical line from the centre of gravity to the ground.

Question 29

Displacement

Answer 29

Change in position, from a to b.