momimp

momimp - , F net dt = p , where the impulse of a force is...

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Linear momentum and the impulse-momentum theorem Definition of linear momentum of a particle Consider a system of N particles, each with a position vector, r i . The i th particle has mass m i and velocity, v i . We define the linear momentum of the particle by p i m i v i . The linear momentum of the system of particles is then written P Σ i p i . Next, we contemplate how to change the value of p for a particle. Obviously, the mass can not change and therefore to change p we must do it by changing v , i.e we must accelerate the particle. Newton’s second law gives F net = m d v /dt = d [m v ]/dt = d p /dt. This becomes for a system of particles, F ext net = d P /dt, Where, F ext net is the sum of only the external forces acting on the particles of the system.
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Rearranging gives the impulse-momentum theorem
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Unformatted text preview: , F net dt = p , where the impulse of a force is defined, I F dt. this is the area under F vs t graph For example, F net t = F net t = p where the average force is used. A consequence of the impulse-momentum theorem is the law of conservation of momentum : If the net external force acting on a system is zero, then the momentum of the system is constant. An important application is to collisions. In the simplest case we consider the collision of two particles in one-dimension, of which there are two extreme regimes. completely inelastic Only momentum of the two-body system is conserved. Elastic Both momentum and kinetic energy of the two-body system is conserved. EXAMPLES [in class]...
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momimp - , F net dt = p , where the impulse of a force is...

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