Physics 101 Formulas
Kinematics
vave =
Dx/Dt
aave = Dv/Dt
v = v0 + at
x = x0 + v0t +
1/2at2
v2 = v02 + 2aDx
g=9.81m/s2 = 32.2ft/s2
Dynamics
SF = ma
Fg = Gm1m2 / R2
Fg = mg (near earths
surface)
fs,max = msFN
fk = mkFN
ac = v2 / R =
w2R
Work & Energy
WF =
FScos(q) KE =
1/2mv2 WNET
= DKE = KEf -
KEi
Wnc = DE = Ef - Ei = (KEf + PEf)
- (KEi + PEi)
Wgrav = -mgDy PEgrav = mgy
Impulse & Momentum
Impulse
I = FaveDt = Dp
FaveDt = Dp = mvf -
mvi
Fave
= Dp/Dt
SFext Dt= DPtotal =
Ptotal,final -
Ptotal,initial
(momentum conserved if SFext = 0)
Xcm =
(m1x1+
m2x2) /
(m1+m2)
Rotational Kinematics
w = w0 + at
q = q0 + w0t +
1/2at2 w2 = w02 + 2aDq
vT = wR aT =
aR ( so for rolling
without slipping v = wR a = aR )
Rotational Statics &
Dynamics
t =
FL (L is lever arm= distance from line
of force to rotation axis)
St = 0 and SF=0 (static
equilibrium)
St =
Ia
I = Smr2 (for a
collection of point particles)
I =1/2MR2 (solid disk or cylinder)
I =2/5MR2 (solid
sphere) I
=2/3MR2 (hollow sphere)
I =MR2 (hoop)
W = tq (work done
by a torque)
L =Iw
Stext Dt = DL (angular momentum conserved if
Stext =
0)
KErot=1/2Iw2 =L2/2I
KEtotal=KEtrans +
KErot =
1/2mv2 + 1/2Iw2
Simple Harmonic Motion
Hookes Law:
Fs=
-kx
Wspring =
1/2kxi2 -
1/2kxf2
PEspring = 1/2kx2
For a mass on a spring x(t) =
Acos(wt)
or x(t) = Asin(wt)
w2 = k/m, T =
2p/w, f = 1/T
xmax= A
vmax=
wA amax=
w2A
For a simple pendulum w2 = g/L
Fluids
P2 = P1 +
rg(y1-y2) change in pressure with depth
Buoyant
force FB = rgVdis
= weight of displaced
fluid
Flow rate Q = v1A1 = v2A2 continuity equation
(area of circle A = pr2)
P1 + 1/2rv12 + rgy1 = P2 + 1/2rv22 + rgy2 Bernoulli
equation
rwater = 1000
kg/m3 1m3 = 1000
liters
r =
M/V