Linear Kinematics: x = (vf + vi)/2 V t a v , t a dv = slope of a velocity vs time graph dt Dynamics Σ F ma, Ff FN d2x a 2 dt v 2f v 02 2ax Range equation: R = 2V o 2 (sin 2φ)/g = horizontal distance traveled if shot at angle 1 x v f t at 2 2 1 x v 0 v f t note: this is just average speed x time 2 x( or distance traveled) = ∫ v dt = area under a speed vs time graph vectors: never mix x and y dx 1 v x v 0t at 2 , dt 2 Fg G vectors: never mix x and y ixj=k w mg but against circle j x i = -k ( s is a maximum therefore can be less than calculated, and k is constant) m1m2 r2 Fc mac , Fc m v2 , r Fs kx scalars. Direction is less important….easier……very little trig. Dot product yields scalar projections: i∙i = 1, i∙j = 0 Energy: W F d Fd cos , W Fdxcos = area under an F vs distance graph W K , W U U g mgh on a planet, mm Ug G 1 2 between objects (like Earth and Sun, apple and moon) r 1 2 K mv 2 Total Mechanical Energy E = K + U For satellites in circular orbit Fc =Fg to find orbital velocity U = K to find escape velocity K = -U/2 and E = -GMm/2r where are is the separation between centers U i Ki U f K f if gravity is the only force in play 1 Us kx2 2 F = -dU/dx = negative of slope on a U vs x graph. Know shapes of stable, unstable and neutral equilibrium. W = dU/dt t P Fv used mainly when sliding an object against friction at constant speed P Momentum vectors again; separate x and y dp = slope of a momentum vs time graph p mv , pi p f , F dt J mv , J Ft , J Fdt = area under an F vs t graph & Oscillation Rotation 2π radians = 360° , t 1 0 t t 2 2 , t v r s r d dt at r d dt 1 i f t 2 Fc m 2 r CM calculation: Pick a convenient origin then do z Xcm = Σmx/Σm. Next do y and If there is no outside force acting, the motion of the CM will remain unchanged. If an outside force is acting, F =ma find the acceleration of the CM. If you are rotating about the CM Other shapes us I r dm, 2 I mr 2 Ihoop = mr2 I disk = ½ mr2 I r 2dV (called a volume integral if you did it in calculus) If you are rotating about any axis a distance d from the center of mass I p Icm Md 2 1 K r I 2 2 L I , I , rF sin = rxF (RHR for direction) L mvrsin Kepler: for any satellite about a central star 4 2 T 2 ksa 3 , k s , (k goes to 1 when AU’s and Years are used) Gms l m Tp 2 Ts 2 g k I for the rocking oscillation of any shape of known I mgd 2r 2 x Acost where A is the amplitude. (or use sine) v T T d2x a A 2 cost , a 2 , a 2 x v dx / dt A sin t , dt Tcp 2