Biomechanics: Biomechanical Principles

Question 1

Define momentum and state its unit of measurement

Answer 1

Mass x velocity
Kilogram metres per second (KGM/S)

Question 2

Name Newton’s first law of motion

Answer 2

Law of inertia

Question 3

Explain Newton’s first law of motion

Answer 3

• The performer will remain stationary until an external force Is applied
• The performer will travel with a constant velocity until another force is applied
• External force is applied by the performer’s muscles

Question 4

Name Newton’s second law of motion

Answer 4

Law of acceleration

Question 5

Explain Newton’s second law of motion

Answer 5

The rate of change of momentum of a body is directly proportional to the force causing it and the change takes place in the direction in which forces the act

Question 6

Name Newton’s third law of motion

Answer 6

The law of action-reaction

Question 7

Explain Newton’s third law of motion

Answer 7

To every action there is an equal and opposite reaction

Question 8

Define stability

Answer 8

The ability to maintain a centre of mass over a base of support

Question 9

Name 3 factors that affect stability

Answer 9

1. Height of centre of mass
2. Size of base of support
3. Line of gravity
4. Mass

Question 10

How does height of centre of mass effect stability?

Answer 10

The lower the centre of mass, the more stable a performer

Question 11

How does the size of base of support effect a performer’s stability?

Answer 11

The wider the base of support, the more stable the performer

Question 12

How does line of gravity effect a performer’s stability?

Answer 12

The closer the line of gravity to base of support, the grater the stability

Question 13

How does mass effect a performer’s stability?

Answer 13

The greater the mass of the object/performer, the greater the stability

Question 14

Define impulse

Answer 14

Force x Time

Question 15

Explain the forces of an impulse at the start of a 100m race

Answer 15

• Small Negative (Landing)force
• Large Positive (Push off) Force
• Net force is Positive
• Causes performer to accelerate

Question 16

Explain the forces of an impulse during a 100m race

Answer 16

Both Negative landing force and positive push of force are equal

Net force is 0

Performer will travel at a constant velocity.

Question 17

Explain the forces of an impulse during the end part of a 100m race

Answer 17

• Large negative landing force.
• Small positive push off force.
• Net force is negative.
• Performer will decelerate.