Allowed Equations
Equations below may be used as starting equations for solving problems. If the equation you
want to use isn’t on this sheet, you’re not allowed to use it as a starting point unless the problem
states otherwise.
vav = Δx/Δt
aav = Δv/Δt
vav = ½(vo + v)
g = 9.80 m/s2
v = vo + at
x = xo + ½(vo + v)t
Fnet = ma
W = mg
fk = µkN
Wi = Fidcosθ Ug = mgy
Ue = ½kx²
K = ½ mv²
Wnet = ΔK
fs <= µsN
P = W/t = Fv
ΔFres = -kΔx
ΔU = -Wc
x = xo + vot + ½ at 2
a = v²/R
Wext = ΔEsys
v 2 = vo2 + 2a( x − xo )
v = 2πR/T
Emech = K + U
Useful identities
sin2θ + cos2θ = 1
o
90
30o
37o
45o
53o
60o
sinθ /cosθ = tanθ
1
sinθ = cos(90°- θ)
½
3/5 sqrt(2)/2 4/5 sqrt(3)/2
0
sinθ = -sin(-θ)
sqrt(3)/2 4/5 sqrt(2)/2 3/5
½
cosθ = cos(-θ)
sqrt(3)/3 ¾
1
4/3 sqrt(3) infinite
Values of the trigonometric functions for some common angles
0o
θ
sinθ 0
cosθ 1
tanθ 0
c2 = a2 + b2
sinθ = a/c
cosθ = b/c
tanθ = a/b