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Momentum. September 21, 2010. Momentum. Linear A vector that depends on two physical quantities: the mass and the velocity of the moving object Angular The momentum of a rotating object (not covering this yet) In all cases, momentum is CONSERVED. FORMULA : p = m Δ v.
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Momentum September 21, 2010
Momentum • Linear • A vector that depends on two physical quantities: the mass and the velocity of the moving object • Angular • The momentum of a rotating object (not covering this yet) • In all cases, momentum is CONSERVED. • FORMULA: p = mΔv
Conservation of Momentum • the total momentum of a closed system of objects is CONSTANT pi = pf mΔvi = mΔvf If there are 2 objects… m1Δvi1+ m2Δvi2 = m1Δvf1 + m2Δvf2 • In collisions, we will have to break down momentum into x & y dimensions pix = pfx piy = pfy
Impulse • An impulse is a force given to an object over a change in time. This impulse changes the objects momentum. • Momentum (our next unit) is found by multiplying an object’s mass by its velocity • Impulse = the variable “J” • J = Ft = mv • We need to include impulses in our F equations
Conservation of Energy • In all processes, energy is conserved Ei = Ef • We are going to look at 2 types of energy • Kinetic= the energy of motion= ½ mv2 • Can an object have kinetic energy if it is at rest? • Potential = the energy of position = mgh =(mass)(10m/s2)(height) • If something is at ground level, will it have potential energy? Ei = Ef KEi + PEi = KEf + PEf ½ mvi2 + mghi = ½ mvf2 +mghf