Newtonian Physics Flashcards
What is Newtonian Physics?
The description of mechanical events—those that involve forces acting on matter—using the laws of motion and gravitation
What is the definition of gravity?
A unidirectional force that pulls objects down towards earth’s center
Gravity pulls on all objects with a force of _______.
9.81 m/sec per sec (32ft/sec per sec)
Who created the law of gravity?
Sir Isaac Newton
What is the formula for gravity (be able to understand each part and what happens to the gravity force when one component is changed)?
Gravitational force= (G x m1 x m2)/d squared)?
G = Gravitational constant-(6.67 × 10−11Nm2/kg2)
m1 and m2 = masses of the two objects used to calculate force
d = distance between the centers of gravity of the two masses
Mass and weight are ______
not equivalent.
What is mass?
Mass is the total of all matter in an object—the sum of the mass of all the electrons, protons, and neutrons.
What is weight?
Weight is the total effect of gravity pulling on all the electrons, protons, and neutrons contained in an object
How is weight effected by gravitational pull?
Dependent
How is mass effected by gravitational pull?
Non dependent
Will the mass of an eraser be the same on Earth and the Moon?
Yes
Will the weight of an eraser be the same on Earth and the Moon?
No. Weight is the pull of other massive bodies on the object, and therefore does depend on the location of the object with respect to objects such as planets.
What is the formula for determining weight?
Mass x force of gravity= weight
What is the SI unit of measurement for weight?
Newton
Why do we measure our patient’s weight in kg instead of Newtons?
Because gravity is constant, we don’t need to distinguish between mass and weight
For a patient whose mass is 80 kg, what is their weight in Newtons?
Mass (kg) x Force of Gravity (9.81 m/sec2) = Weight (N)
80kg x 9.81 m/sec2 = 784.8 N
What is gravitational acceleration?
Gravity causes objects with mass to accelerate towards each other.
What two factors effect the rate of gravitational acceleration?
Mass of the objects and their proximity
Gravitational acceleration: The more mass an object contains, the _____ it will attract other objects
more
Gravitational acceleration: The closer an object is to another the _____ the attraction between them will be
greater
How does increasing object mass effect force and acceleration?
One might want to say that objects with greater mass would accelerate or be pulled faster to earth, but objects also resist movement proportional to their mass (third law of motion). Objects with greater mass are pulled by gravity with the same force and fall at the same acceleration as objects with lesser mass.
What would lead to decreased gravitational pull?
Friction-Greater friction equals greater force against the pull of gravity and slowing of a fall
What causes friction?
Air molecules possess energy, move about, and interact with other matter (friction)
Gravitational acceleration is _______ to the distance of the object to the center of the Earth
inversely proportional
How many laws of motion are there?
3
What is the first law of motion (Law of inertia)?
A body in motion tends to stay in motion unless acted upon by another force
What is the second law of motion (law of acceleration)?
Acceleration of a body is in the direction of and proportional to the force (F), and that acceleration is inversely proportional to the mass (m) of the body
What is the formula for force?
Force= mass x acceleration
If multiple forces (VECTORS) exist, the direction and acceleration are _______to the sum of all the forces
proportional
Objects with greater mass have more _______
Inertia
What is the third law of motion (law of reciprocal action)?
For every action, there is an equal and opposite reaction. Objects exert equal but opposite forces on one another
What is force?
Amount of energy required to move an object
How are the mass and force of an object relate?
Equally proportional
What is a newton?
The newton (N) is the standard measure of force derived from the force of gravity. The force required to accelerate a 1 kg weight 1 m/sec
True or false. If an object has a net force of 0 then it has no forces acting on it
False. Still forces acting on an object when net force= zero
What is the acceleration of a 1 kg mass object if you apply 1 Newton of force to it?
1 m/ms2
How much does 1N weigh on earth (g)?
102 g
How much does 1N weigh on earth (kg)?
1/9.81 or 0.102
Meters per second per second is a measure of?
Acceleration
What two factors describe vectors?
Magnitude and direction
What are vector diagrams?
Scaled representations of vectors, with an arrow starting at a given magnitude and pointing in the direction of the force summation.
What is an example of a vector diagram?
Electrocardiogram (ECG) is a type of vector diagram that allows us to calculate the predominant direction of electrical force in the myocardium.
What effects scalers?
magnitude only
Vectors on EKG: When the flow is toward the positive electrode, an ____ deflection will record
Upward
Vectors on EKG: When the flow is away from the positive electrode, an ____ deflection will record
Downward
Vectors on EKG: As multiple points of reference are recorded, the _______ of electrical flow may be determined
Predominant Direction and can determine axis deviation of the heart
What type of deflection will be represented in V4, V5 AND V6?
Mostly positive (Upward deflection)
What type of deflection will be represented in V2 & V3?
Isoelectrical- transition zone
What type of deflection will be represented in V1?
Mostly negative (Downward deflection)
A downward shift towards V1 & V2 can be indicative of what physiological disease?
Right ventricular hypertrophy
What is pressure?
Pressure is defined as force over area, where P is pressure, f is force, and a is area.
What happens to pressure as you increase the area you are applying the force?
Decreases or Lowers
What happens to pressure as you decrease the area that you are apply the force?
Increases or Greater
What is the standard unit of measure for pressure?
Pascal
What is atmospheric pressure?
The gravitational force on gases in a given area/atmosphere.
What causes atmospheric pressure?
The cumulative effect of gravity on atmospheric gases gives rise to atmospheric pressure
When is atmospheric pressure most concentrated?
Sea level
When is atmospheric pressure least concentrated?
Higher altitudes
How many mmHg is atmospheric pressure?
760 mmHg or 100 kPa (SI)
What device is used to measure pressure?
Manometer
How does a manometer work?
Liquid-filled tube open to atmospheric pressure on one end and exposed to a pressure for measurement on the other end. A pressure greater than atm pressure will displace the column of liquid proportional to the pressure difference (∆h).
What type of measurement is BP?
Gauge pressures that are zeroed to atmospheric pressure
What is an example of a healthcare device that measures pressure?
Sphygmomanometer
What is oscillometry?
Automates noninvasive BP measurements by recording oscillations in pressure caused by arterial pulsation
BP reading: When will oscillations increase?
Systolic pressure
BP reading: When will oscillations reach maximal?
MAP
What type of principle is used by invasive BP monitors?
Use a piezoelectric transducer that converts pressure waves to electrical signals
What causes the voltage produced on an IBP?
Piezoelectric- when small amounts of pressure are applied, a small voltage is produced from the changing charge created by the moving electrons.
What factors make up absolute pressure?
Atmospheric pressure plus gauge pressure
What factors make up Gauge pressure?
absolute pressure – atmospheric pressure
What will gauge pressure be at 0?
760 mmHg
What is a bourdon gauge used for?
Used in anesthesia to measure high pressures (gas cylinders)
Where is zero on the bourdon gauge?
Atmospheric pressure
How does the bourdon gauge work?
Contain a coiled tube that expands as pressure is applied. A linkage connects the coil to a rotating arm that records pressure.
What affects the behavior of matter?
Temperature and Pressure
273.15k = ______C
0C
100 kPa = ________ atm
0.986 atm
101.325= ______ atm
1
What measure is used to express small measures of force?
Dyne
Dyne equals how many newtons?
1000th
What is a dyne?
The force required to move 1g of weight 1 cm per second
What is dyne commonly used to calculate in healthcare?
Systemic and pulmonary vascular resistance (PVR).
What is PVR?
The measure of the pulmonary vascular system’s resistance to flow from the right ventricle
What is normal PVR?
100 to 200 dyne sec/cm5
What is SVR?
The measure of the peripheral vascular system’s resistance to flow that must be overcome for flow to occur.
What is normal SVR?
900 to 1200 dyne sec/cm5
How do you calculate SVR?
80 × (MAP − CVP)/CO = SVR
What is accelerometry?
Used to measure the degree of neuromuscular blockade, uses a piezoelectric disk to generate an electric current in proportion to acceleration
What does an accelerometer measure?
The acceleration caused by the contraction of the adductor pollicis muscle after ulnar nerve stimulation
Why is an accelerometer important over a TOF?
Accelerometers provide objective twitch data referenced to the patient’s baseline twitch response