Stability and Lever Systems

Question 1

What is ‘centre of mass’?

Answer 1

The point at which a body is balanced in all directions

Question 2

What is the ‘Fosbury Flop technique’ for high jump?

Answer 2

• Uses a j-curve to allow greater velocity in the approach
• Plants the outside foot to allow the inside leg to lift, along with the arms, at take-off to raise the centre of mass as high as possible
• Fully extends the spine to rotate around the barmoving the centre of mass outside of the body and below the bar.

Question 3

What is stability?

Answer 3

The ability of a body to resist motion and remain at rest

Question 4

What factors affect stability?

Answer 4

• Mass of the body
• Height of the centre of mass
• Base of support
• Line of gravity

Question 5

How can stability be maximised?

Answer 5

Crouching, with both hands and feet on floor

Question 6

How can stability me minimised?

Answer 6

raising centre of mass, having lass bases of support

Question 7

What are the 4 components of a lever?

Answer 7

• Lever (bone)
• Fulcrum (joint)
• Effort (muscular force)
• Load (weight/resistance)

Question 8

Describe a FIRST class lever.

Answer 8

The fulcrum is in the centre, with the effort and load either side of the lever.

Question 9

Describe a SECOND class lever.

Answer 9

The load is in the centre with the effort and fulcrum at either end.

Question 10

Describe a THIRD class lever.

Answer 10

The effort is in the centre, with the load and fulcrum at either end of the lever.

Question 11

Which lever is seen as a mechanical advantage?

Answer 11

The second-class lever system, as the effort arm is greater than the load arm. This means that a large load can be moved with a relatively small effort