Key Equations

Sections
Key Equations

Key Equations

resultant magnitude R= R x 2 + R y 2 R= R x 2 + R y 2
resultant direction θ= tan 1 ( R y / R x ) θ= tan 1 ( R y / R x )
x-component of a vector A (when an angle is given relative to the horizontal) A x =Acosθ A x =Acosθ
y-component of a vector A (when an angle is given relative to the horizontal) A y =Asinθ A y =Asinθ
addition of vectors A x  +  A y  = A A x  +  A y  = A
angle of displacement θ= tan 1 (y/x) θ= tan 1 (y/x)
velocity v= v x 2 + v y 2 v= v x 2 + v y 2
angle of velocity θ v = tan 1 ( v y / v x ) θ v = tan 1 ( v y / v x )
maximum height h= v 0y 2 2g h= v 0y 2 2g
range R= v 0 2 sin2 θ 0 g R= v 0 2 sin2 θ 0 g
force of static friction f s μ s N f s μ s N
force of kinetic friction f k = μ k N f k = μ k N
perpendicular component of weight on an inclined plane w =wcos(θ)=mgcos(θ) w =wcos(θ)=mgcos(θ)
parallel component of weight on an inclined plane w || =wsin(θ)=mgsin(θ) w || =wsin(θ)=mgsin(θ)
Hooke’s law F=kx F=kx
period in simple harmonic motion T=2π m k T=2π m k
frequency in simple harmonic motion f= 1 2π k m f= 1 2π k m
period of a simple pendulum T=2π L g T=2π L g