basics of physics week 1 Flashcards
Newtons first law
an object in motion will stay in motion unless an external force acts upon it. also known as the law of inertia.
does an object with a greater mass require more force to move it? T/F
True
Force =’s ?
Mass times Acceleration
Newtons second law
The second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object.
are force and acceleration both vectors T/F?
true
Newtons third law
For every action, there will be an equal and opposite reaction.
what is velocity?
velocity describes how the position of an object changes over time. V= displacement/ Time
Is velocity a vector? T/F
true
speed is ?
it is a rate of motion. rate of change in position. speed is a scaler value. it implies no particular direction. avg speed = distance/time. it is always positive.
velocity is ?
speed with direction. change in direction over a given time. velocity involves displacement. which is a change in a position with respect to an origin.
what is a vector?
a quantity having direction as well as magnitude, especially as determining the position of one point in space relative to another.
vectors have two things?
Magnitude and direction
Is mass a vector quantity?
NO
can you add vectors togeather? T/F
True. example is Suppose you are walking 5mph south on a train moving 30mph south. what is your resulting velocity? 5+30=35 mph
what is acceleration?
it describes how velocity changes with time.
Is acceleration a vector?
yes, it is. so changing direction also causes acceleration.
Acceleration measurement?
M/s squared. acceleration can occur with a change in speed, direction, or both.
for projectiles a is the acceleration downward due to gravity what is it?
9.8 m/s squared downward.
can velocity be negative?
yes it can if its in the opposite direction of its acceleration.
what is force?
it is a push or a pull.
what is force related to? and which of newtons laws?
it is related to mass and Newton’s second law. F=m(a)
is force required to produce an acceleration? T/F
True
what is gravity? and which law of newtons ?
it is the universal attraction between all objects. newtons third law
what is the gravity of earth?
9.8 m/s squared. or 32.2 ft/s squared
what is weight?
it is the gravitational force exerted on an object by another larger object like the earth. W= m(g) m=mass g= gravity.
is weight a force?
yes thus it causes acceleration. comparable with F=m(a)
Si unit of mass? and English unit of mass? Si unit of force?
SI mass= Kg Kilogram English = slug = 14.6 kg SI force= newton example is 9.8N= (1kg) x ( 9.8m/s squared) W= (m)g
what is mass
amount of matter in an object
English unit of force?
pound. example weight of one slug mass on the surface of the earth. 32.2 lb= (1slug) x ( 32.2ft/s squared)
calculate the mass in kg and weight in N of a 150 lb person.
150/32.2 = 4.66 slug 4.66slug x 14.6 = 68 kg mass 68 x 9.8N/kg = 639N = weight in newtons.
what is pressure?
pressure = Force/ area pressure is force per unit area Pressure can be increased by either increasing the applied force or by decreasing the area the force is applied. and vice versa.
units of pressure (important) (slide 19)
pounds per square inch. (PSI) also know in Pascal (Pa) = 1 newton per square meter however, 1 Pa is tiny so we use Kilopascals (kPa) Torr or mmHg ( 1 Torr = 1 mmHg) atmosphere (atm) Bar 1 atm = 760 torr= 760 mmHg = 101325 Pa 1 atm = 1.013 bar 1 bar = 100,000 Pa = 10 to the 5th Pa= 100 kPa
mmHg is equal to?
the amount of pressure to suspend a column of mercury 1mm in height.
atm is measured in what?
inches of mercury and usually referenced to sea level.
formula for pressure
pressure = Force/ area syringe video example (slide 21)
atmospheric pressure
results from gravity pulling on the atmosphere, and the resulting force is spread over all earths surface. atmospheric changes depend on distances from sea level. ex. pressure in Denver is less then new Orleans this also affects oxygen and gas concentrations of inspired inhalation anesthetics.
Barometer ( slide 24)
instrument used to measure atmospheric pressure.
manometer (slide 25)
used to measure pressure differences.
Aneroid gauge ( slide 26)
means without liquid greek. rely’s on expansion and contraction of bellows as pressure changes.
Aneroid style gauge is found on what? (slide 27) also called a Bourdon Gauge.
gas cylinder such as oxygen, air, and Nitrous oxide.
this type of gauge measures gas not liquid?
Bourdon gage. even when the tank is empty it still has 14.5 psi or atmospheric pressure.
daltons law of partial pressure
air is 21% nitrogen 79%
gauge pressure and total pressure
suppose a tank of gas has a gauge pressure that reads 45 psi. if the atmospheric pressure is at that time 14 psi, how much gas is really in the tank? P total = P gauge + Patm so 45psi+ 14psi = 59 psi
1 atmosphere is = to ?
14 psi
non- invasive blood pressure is called
oscillometry. relies on oscillations.
what is a transducer
device that interconverts a signal between nonelectric and electrical domains.
piezoelectric transducer
non-electric pressure changes that impact the transducer creating a voltage that is proportional to the pressure change
