Biomechanics - Momentum, Levers Etc.

Question 1

Newton’s First Law of Motion

Answer 1

Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed on it.

Question 2

Newton’s Second Law of Motion

Answer 2

Force is equal to the change in momentum per change in time. For a constant mass, force equals mass times acceleration.

Question 3

Newton’s Third Law of Motion

Answer 3

For every action there is an equal and opposite reaction.

Question 4

Equation for Force

Answer 4

F=ma

Question 5

Momentum

Answer 5

Momentum is the tendency for an object in motion to continue in that way, it is proportional to mass times velocity.

Question 6

Formula for Momentum

Answer 6

p=mv

Question 7

Conservation of Momentum

Answer 7

This states that the amount of momentum and energy within a collision is always constant, within an ideal environment. For instance, a snooker ball coming and and hitting another would cause its momentum to be shifted to the other one.

Question 8

Impulse

Answer 8

• Impulse refers to when a force is applied to an object, and is measured in Newton seconds (Ns)
• The longer contact is held with the projectile, the more force that can be applied.

Question 9

Formula for Impulse

Answer 9

• Impulse = ft

- Impulse = mv-mu

Question 10

Elasticity

Answer 10

Elasticity refers to how well an object can return to its original form and position after impact.

Question 11

Formula for Coefficient of Restitution

Answer 11

• COR = square root of height of rebound / height of drop
• COR = velocity after collision / initial velocity
• COR = S2-V2 / V1-S1

Question 12

Moment of Inertia

Answer 12

• An objects resistance to rotational motion

Question 13

Formula for Moment of Inertia

Answer 13

I = mr^2

Question 14

Angular Momentum Formula

Answer 14

Angular momentum = angular velocity x moment of inertia

Question 15

First Class Lever

Answer 15

• Fulcrum located between the resistance and the point of force.
• Most effective lever

Question 16

Second Class Lever

Answer 16

• Fulcrum is located at the end of the Lever

- Resistance is between the fulcrum and force.

Question 17

Third Class

Answer 17

• Fulcrum at the end of the lever while the force is applied between the load and the fulcrum
• Most levers in the body fall into this category

Question 18

Force Arm

Answer 18

• The distance from the point of force to the fulcrum

- Longer force arm = less effort required to move a resistance

Question 19

Resistance Arm

Answer 19

• Distance from load to fulcrum

- The longer the resistance arm, the quicker the system can move.

Question 20

Mechanical Advantage

Answer 20

• The optimum strength:length of lever ratio.

- Mechanical advantage = force arm / resistance arm

Question 21

Torque

Answer 21

• Torque is equal to the force applied multiplied by its perpendicular distance from the fulcrum.
• The longer a lever, the more torque.