# Physics 12 formula and representation sheetnn## Frames / relativityn- vec v_{A/C}=vec v_{A/B}+vec v_{B/C}n- gamma=1/sqrt{1-v^2/c^2}n- Delta t=gammaDelta t_0, L=L_0/gamman- p=gamma mv, E^2=(pc)^2+(mc^2)^2nn## Equilibrium / circular motionn- sum F_x=0, sum F_y=0, sumtau=0n- tau=rFsinthetan- a_c=v^2/r, F_{net,r}=mv^2/rnn## Gravitationn- F_g=Gm_1m_2/r^2, g=GM/r^2n- U_g=-GMm/rn- v_{orb}=sqrt{GM/r}, T=2pisqrt{r^3/(GM)}, v_e=sqrt{2GM/r}nn## Electrostaticsn- F=k|q_1q_2|/r^2, E=F/q=k|Q|/r^2n- V=kQ/r, U=qV, EapproxDelta V/d for ideal platesn- Delta K=-qDelta Vnn## Magnetism / inductionn- F=|q|vBsintheta, F=ILBsinthetan- r=p/(|q|B)n- Phi_B=BAcosthetan- |mathcal E|=N|DeltaPhi_B/Delta t|n- Ideal transformer: V_s/V_p=N_s/N_p, V_pI_papprox V_sI_snn## Momentum / graphsn- p=mv, J=Delta p=int Fdtn- Isolated system: sumvec p_i=sumvec p_fn- Elastic collision also conserves total Kn- Slope m=Delta y/Delta x; graph area inherits product units and meaning from the model.n