Physics 50 Equation Sheet r v v s rf ri r t dr dt Us=(1/2)kx2 Elastic PE Function Average velocity Emech=K+U Total Mechanical Energy Wnc Instantaneous velocity Average Speed t Average acceleration v t dv d 2 r a dt dt 2 v vo at a Instataneous acceleration x xo vot (1/ 2)at 2 v2 vo2 2a( x xo ) x Displacement Velocity as function of time Position as function of time Velocity as function of position Position as function of velocity and time vo v t 2 xo v2 ar r F ma w mg fk kN Radial (centripetal) acceleration fs s Static frictional force W F s Fs Ws kx 2 i (1/ 2)kx (1/ 2)kx Kf Ki W t dW P dt P F v Fv cos Ug=mgy Pave= 2 f Work done by constant force Spring force (Hooke’s Law) Work done by spring force Work done by applied force Wapplied= - Ws K=(1/2)mv2 Wnet P MV dP Fext dt I Fext (t 2 I p2 p1 v2 f s (v2i v1i ) Average angular acceleration t d dt o Impulse due to a constant net force Impulse-Momentum Theorem Relative velocities in an elastic collision Arc length Average Angular Speed Instantaneous Angular Speed Instantaneous angular acceleration d2 dt 2 1 2 t ot 2 t Angular position as function of time vt r Angular speed as function of time Angular speed as function of angular position Angular position as function of angular speed and time Tangential speed at r Tangential acceleration o 2 2 o 2 ( o o 2 Work-Energy Theorem ar Average power I v2 r r mi ri 2 Instantaneous power Ip I cm Instantaneous power Gravitational PE Function (constant g) t1 ) p t d dt Kinetic energy K v1 f Newton’s 2nd Law r Weight of a body Kinetic friction force Fs cos Work by non-conservative forces Conservation of Mechanical Energy Linear Momentum U Ki+Ui = Kf+Uf Newton’s 2nd Law N K KR 1 I 2 r F I ext 2 o t ) Radial (centripetal) acceleration Md 2 Moment of Inertia for System of Particles Parallel-Axis Theorem 2 Rotational kinetic energy Definition of Torque Newton’s 2nd Law for Rotation Work Done by a constant Torque Work-Energy Theorem for Rotation W W P 1 I 2 W t 1 I 2 2 f 2 i Average power delivered by Torque P K 1 MVcm2 2 vcm R a cm R L r L 1 I cm 2 Angular momentum p I dL dt Gm1m2 r2 GmM E Fg RE GM E ext Fg wE g RE U v esc v T E 2 2 Instantaneous power delivered by Torque Kinetic Energy = Translational KE + Rotational KE Condition for Rolling Without Slipping h Angular momentum for a rotating body about axis of symmetry Newton’s 2nd Law for rotation Newton’s Law of Gravitation Weight of a body at surface of earth Acceleration of gravity 2 GMm r 2GM R Gravitational Potential Energy function GM r Circular Orbit Speed Escape Speed Orbital Period 4 2 3 r GM GMm 2r 1 U 2 Orbital Total Mechanical Energy