Key Equations

Key Equations

Position vector r→(t)=x(t)i^+y(t)j^+z(t)k^r→(t)=x(t)i^+y(t)j^+z(t)k^
Displacement vector Δr→=r→(t2)−r→(t1)Δr→=r→(t2)−r→(t1)
Velocity vector v→(t)=limΔt→0r→(t+Δt)−r→(t)Δt=dr→dtv→(t)=limΔt→0r→(t+Δt)−r→(t)Δt=dr→dt
Velocity in terms of components v→(t)=vx(t)i^+vy(t)j^+vz(t)k^v→(t)=vx(t)i^+vy(t)j^+vz(t)k^
Velocity components vx(t)=dx(t)dtvy(t)=dy(t)dtvz(t)=dz(t)dtvx(t)=dx(t)dtvy(t)=dy(t)dtvz(t)=dz(t)dt
Average velocity v→avg=r→(t2)−r→(t1)t2−t1v→avg=r→(t2)−r→(t1)t2−t1
Instantaneous acceleration a→(t)=limt→0v→(t+Δt)−v→(t)Δt=dv→(t)dta→(t)=limt→0v→(t+Δt)−v→(t)Δt=dv→(t)dt
Instantaneous acceleration, component form a→(t)=dvx(t)dti^+dvy(t)dtj^+dvz(t)dtk^a→(t)=dvx(t)dti^+dvy(t)dtj^+dvz(t)dtk^
Instantaneous acceleration as second
derivatives of position
a→(t)=d2x(t)dt2i^+d2y(t)dt2j^+d2z(t)dt2k^a→(t)=d2x(t)dt2i^+d2y(t)dt2j^+d2z(t)dt2k^
Time of flight Ttof=2(v0sinθ0)gTtof=2(v0sinθ0)g
Trajectory y=(tanθ0)x−[g2(v0cosθ0)2]x2y=(tanθ0)x−[g2(v0cosθ0)2]x2
Range R=v02sin2θ0gR=v02sin2θ0g
Centripetal acceleration aC=v2raC=v2r
Position vector, uniform circular motion r→(t)=Acosωti^+Asinωtj^r→(t)=Acosωti^+Asinωtj^
Velocity vector, uniform circular motion v→(t)=dr→(t)dt=−Aωsinωti^+Aωcosωtj^v→(t)=dr→(t)dt=−Aωsinωti^+Aωcosωtj^
Acceleration vector, uniform circular motion a→(t)=dv→(t)dt=−Aω2cosωti^−Aω2sinωtj^a→(t)=dv→(t)dt=−Aω2cosωti^−Aω2sinωtj^
Tangential acceleration aT=d|v→|dtaT=d|v→|dt
Total acceleration a→=a→C+a→Ta→=a→C+a→T
Position vector in frame
S is the position
vector in frame S′S′ plus the vector from the
origin of S to the origin of S′S′
r→PS=r→PS′+r→S′Sr→PS=r→PS′+r→S′S
Relative velocity equation connecting two
reference frames
v→PS=v→PS′+v→S′Sv→PS=v→PS′+v→S′S
Relative velocity equation connecting more
than two reference frames
v→PC=v→PA+v→AB+v→BCv→PC=v→PA+v→AB+v→BC
Relative acceleration equation a→PS=a→PS′+a→S′Sa→PS=a→PS′+a→S′S