phys ct Flashcards
systematic vs random errors
systematic: all readings being above or below the true readings by a fixed amount
random: readings being scattered about a mean value
accuracy vs precision
accuracy: degree of closeness of mean value of measurements to true value
precision: degree of agreement between repeated measurements of the same quantity
4 kinematics equations
v = u + at
s = 1/2 (u+v)t
s = ut + 1/2at^2
v^2 = u^2 + 2as
newtons 1st law of motion
a body a rest will remain at rest or in uniform motion continues in its state in a straight line unless a resultant external force acts on it (inertia)
newtons 2nd law of motion
the rate of change of momentum of a body is proportional to the resultant force acting on it and occurs in the direction of the force
newtons 3rd law of motion
if body a exerts a force on body b, body b exerts an equal and opposite force on body a
mass vs weight
mass: property which results in a change in motion
weight: force experienced by a mass in a gravitational field
action reaction
forces equal in magnitude opposite in direction, same type of forces on 2 diff bodies acting at the same time
impulse
product of force acting on object and time (delta T) for which force acts
principle of conservation of momentum
when bodies in a system interact, total momentum of the system remains constant
impulse formula
delta p = f delta t
elastic collision ke conserved formula
u1-u2 = v2-v1
momentum conserved formula
m1u1+m2u2=m1v1+m2v2
force parallel to slope equation
mg sin theta/mg cos theta
Hooke’s law
extension of body directly proportional to the applied load if limit of proportionality is not exceeded
archimedes principle
upthrust on body in fluid equal to weight of fluid displaced by body
principle of flotation
for object floating in equilibrium, upthrust equal in magnitude and opposite in direction of weight of object
center of gravity
point at where weight of object appears to act
conditions for equilibrium
no net force zero moments
epe formula
1/2kx^2
1/2 fx
pressure in fluid formula
hp(density)g
upthrust formula
weight of fluid displaced = p(density)gv
power formula
force x velocity
energy / time
work done formula
f costheta x s
work done by gas formula
p change in volume
angular velocity
rate of change of angular displacement with respect to time
period formula
time taken to make 1 complete revolution
angular velocity formula
w=v/r
w=2pi/T
w=2pif
centripetal acceleration formula
a=vw
a=rw^2
a=v^2/r
centripetal force formula
f=mvw
f=mrw^2
f=mv^2/r
tension (in circle) formula
t=mv^2/r
formula:
tension cos theta
tension sin theta
tan theta
tcostheta = mg
tsintheta = mv^2/r
tan theta = v^2/rg
centripetal acceleration
acceleration towards center of circular motion
velocity at top of circle formula
N + W = F
N + mg = mv^2/r
when N = 0,
vmin=rootgr
velocity at bottom of circle formula
1/2mvbot^2 = 1/2mvtop^2 + mg(2r)
1/2mvbot^2 = 1/2mgr+mg(2r)
vbot=root5gr
tension/normal force formula
at top and at bottom
ttop/ntop + mg = mv^2/r
stop/ntop = mv^2/r - mg
tbot/nbot - mg = mv^2/r
tbot/nbot = mv^2/r + mg
tension of rod chasing formula
t+mgcos theta = mv^2/r
t = mv^2/r -mg cos theta
gravitational force formula
F = GMm/r^2
newtons law of gravitation
2 point masses attract each other with a force that is directly proportional to the product of their masses and inversely proportionate to the square of distance between them
gravitational field
region in which mass placed in that region experiences a gravitational force
gravitational field strength
gravitational force experienced per unit mass at that point
gravitational potential energy
mass at a point in gravitational field, WD by external force in bringing mass from infinity to that point
gravitational field formula
g=F/m
g=GM/r^2
gravitational potential energy formula
U=-GMm/r
-ve !!
gravitational potential
WD per unit mass by external force in bringing small mass from infinity to the point
gravitational potential formula
theta w line = -GM/r = U/m
-ve as Gf is attractive in nature, bring mass from infinity to a point on field, force opposite in direction of displacement
escape velocity
minimum speed to escape from gravitational influence
escape velocity formula
GMm/Rearth + 1/2 mv^2 >/= o
v = root (2GM/Rearth)
v = root (2 g rearth)
kinetic energy (gravitational field)
1/2 GMm/r
potential energy (gravitational field)
-GMm/r
total energy (gravitational field)
-1/2 GMm/r
for body to orbit around earth formula
GMm/r^2 = mv^2/r
v orbital = root GM/r
GMm/r^2 = mrw^2 = mr(2pi/T)^2
T^2 = 4pi^2/GM r^3
force at equator and polar region
equator: mg = mg-ma
g=g-a (a-centripetal acceleration)
polar region: mg=mg
g=g
Kepler’s third law
gf provides centripetal force necessary for circular motion of plant around sun
square of period of revolution of planets directly proportional to cubes of mean distances from the sun
