15.2 Levers and Balance

Question 1

Describe Centre of Gravity

Answer 1

The point at which all parts of an object are balanced.

Question 2

Describe Base of Support

Answer 2

The area of an object or person that is in contact with the ground

Question 3

Describe Line of gravity

Answer 3

Imaginary line which passes through the centre of gravity and continues down into the centre of an objects base of support

Question 4

Describe a 2nd Class lever using an example from the human body

Answer 4

Resistance in middle, axis and force at either end. Eg when doing a push up or calf raise.

Question 5

Describe a 3rd Class lever using an example from the human body

Answer 5

Force/Effort in middle. Axis and resistance at either end. Most common in human body eg bicep curl.

Question 6

Identify the mechanical advantage of a 2nd class lever

Answer 6

Greater than 1. Allow you to produce more force with less effort

Question 7

Identify the mechanical advantage of a 3rd class lever

Answer 7

Less than 1. They can increase the range of motion and angular speed of the body part

Question 8

Describe the force arm in a lever

Answer 8

the distance from the axis to the force

Question 9

Describe the resistance arm in a lever

Answer 9

distance from the axis to the resistance