eLFH - Newtonian Mechanics

Question 1

Force definition

Answer 1

That which changes, or tends to change the state of rest or motion of an object

Question 2

Force SI unit

Answer 2

Newton

N = kg.m/s^2

Force = mass x acceleration

Question 3

Newton’s first law of motion

Answer 3

In the absence of external forces, an object at rest remains at rest and an object in motion continues in motion with a constant velocity

Question 4

Newton’s second law of motion

Answer 4

The acceleration of an object is directly proportional to the net force acting on it, and inversely proportional to its mass

Summarised by the equation:
Force = mass x acceleration
F = ma

Question 5

Newton’s third law of motion

Answer 5

For every action, there is an equal and opposite reaction

Question 6

Inertia definition

Answer 6

Tendency of objects to resist change in their velocity

Inertia increases with the mass of the object

Question 7

Momentum

Answer 7

Momentum = mass x velocity

P = mv

Question 8

Weight

Answer 8

Force with which an object is pulled by gravity

Force of gravity acting on an object give it acceleration of 9.81 m/s^2

Question 9

Law of conservation of momentum

Answer 9

Provided there are no net external forces acting upon object, the momentum of all objects before a collision will equal the momentum of all objects after the collision

Question 10

Relevance of Newtonian mechanics for anaestheteics

Answer 10

Behaviour of gases - ideal gas molecules obey Newton’s laws of motion

Blood is non-Newtonian fluid

Question 11

How is blood a non-Newtonian fluid

Answer 11

As temperature increases, viscosity of blood decreases

Hence better flow rates when blood is warmed for infusion