kinematics, force, and work Flashcards
what is electric current?
definition: describes the flow of charge in coulombs per second
unit: ampere (A)
what is the temperature conversion from celcius to Kelvin?
273.15+ temp in celcius
factor of 10 given by the prefix deca?
10E1
factor of 10 given by the prefix hecto
10E2
factor of 10 given by the prefix deci
10E-1
factor of 10 given by the prefix centi
10E-2
factor of 10 given by the prefix milli
10E-3
factor of 10 given by the prefix micro
10E-6
factor of 10 given by the prefix nano?
10E-9
factor of 10 given by the prefix pico?
10E-12
what is the derived unit for Force
Kg*m/s^2
what are the units for frequency (SI and derived)
Hertz (Hz)
s^-1
what are the units for pressure (SI and derived)
pascals (Pa)
N/m^2
what are the units for energy/ work
Joule (j)
N*m
what is the SI base unit of electron volt (eV)
1.6E-19 J
what are the units of power
Watts (W)
J/s
what are the units of electrical charge
coulombs (C)
s*A
what are the units of electrical potential
Volt (V) also W/A
what are the units of capacitance
Farads (F)
derived from C/V
what are the units of resistance
ohms
derived from V/A
what are the units of magnetic field
Tesla (T) derived from Wb/m^2
definition of a vector
quantity with magnitude and direction
- typically have x and y components
definition of a scalar
quantity with only magnitude
cos(30)
sqr(3)/2
cos60
1/2
displacement
vector quantity of distance. path independent and is determined by the change in location from starting point. walking in a circle would result in a displacement of zero.
velocity
displacement over time.
units: m/s
acceleration
velocity over time
units: m/s^2 or V/t
if you have a positive velocity how would you interpret if the acceleration was..
A. positive
B. zero
c. negative
A. the object is moving up and speeding up more and more
B. the object is moving up at constant speed
C. object is moving upward and slowing down
if you have a 0 velocity how would you interpret if the acceleration was…
A. positive
B. zero
C. negative
A. object is beginning to move upward from rest , or is moving from downward to upward
B. object is not moving
c. object is beginning to move downward from rest
if you have a negative velocity how would you interpret if acceleration was..
A. positive
B. zero
C. negative
A. object is moving downward and slowing down
B. object is moving downward at a constant speed
C. object is moving downward and speeding up
what does the slope of a displacement vs time graph represent
velocity. the steepness indicates speed
- upward and downward indicate direction
what does the area under the curve of an acceleration vs time graph represent?
velocity
1/2(b*h)
major assumption for kinematic problems on MCAT?
constant acceleration
distance kinematic equation using velocity and time (no acceleration)
d = 1/2 (Vi+Vf)*t
distance kinematic equation with no final velocity?
d = Vit + 1/2at^2
final velocity kinematic equation with no displacement
Vf = Vi + at
final velocity equation with time missing?
Vf^2 = Vi^2 + 2a(delta d )
assumption in free fall problems
constant acceleration
g = -9.8 m/s^2
- no initial velocity!
for projectile motion problems when does Vy = 0
when the object reaches its peak
what is the definition of force?
an objects mass times its acceleration
units : N
derived : Kg*m/s^2
types of force on the MCAT
- gravitational (@ a distance)
- electromagnetic (between charges)
- contact
- normal (against gravity)
- friction
- tension (rope).
- centripital
- spring (using hooke’s law)
Newton’s first law
statement on inertia
object at rest will stay at rest unless acted upon, and an object in motion will stay in motion at a constant velocity unless acted upon
newton’s second law
F= m*a
newton’s third law
force pairs exert force on eachother equally and opposite
F a on B = -F B on A
center of mass
X center = (m1X1 + m2X2) / (m1 + m2)
friction
force that opposes horizontal motion
can be static (Fs) or moving (Fk)
equation for static: FsN
equation for kinetic: FkN
terminal velocity
highest velocity of an object obtained while traveling through a fluid (can no longer accelerate)
how do you calculate the x component of force of gravity on an incline plane?
Fsin(theta)
force of gravity equation
Fg = G (M1M2) / r^2
centripetal acceleration
a = v^2/ r
centripital force
mv^2/r
hooke’s law
-Kx= Force of spring
k is a constant unique to each spring
torque definition and equation
torque is rotational force (at a distance)
T = F * d sin(theta)
what are the ways to increase torque?
increase force
increase distance
rotational potential
t = fd
t = mgd
work
force over a distance
W= fdcos (theta)
unit: J or Nm
- conservative force (independent of path)
mechanical advantage
on a slope, allows for less force with same work
length of slope/ height of slope
power
work done over time
P= w/t also p = V*f
watts
