# Systems of Particles

## Conservation Of Linear Momentum

Conservation Of Linear Momentum Suppose that the net external force acting on a system of particles is zero (the system is isolated) and that no particles leave or enter the system (the system is closed). P = constant If no net external force acts on a system of particles, the total linear momentum P of  the …

## Sample Problem

Sample Problem Race car before and after taking a  turn on a track. Its speed is 0.50 m/s before the turn  after the turn. What is the change in the linear momentum of the car due to the turn? SOLUTION: We treat the car as a system of particles. Then a Key Idea is that to get …

## The Linear Momentum Of a System Of Particles

The Linear Momentum Of a System Of Particles Now consider a system of 11 particles, each with its own mass. velocity, and linear momentum. The particles may interact with each other. and external forces may act on them as well. The linear momentum of a system of particles is equal to the product of the total mass of …

## Linear Momentum

Linear Momentum Momentum is a word that has several meanings in everyday language but only a single precise meaning in physics. The linear momentum of a particle is a vector p, defined as p= mv The time rate of change of the momentum of a particle is equal to the net force acting on the particle and is …

## Sample Problem

Sample Problem The three particles in  are initially at rest. Each experiences an external force due to bodies outside the three system. The directions are indicated. and the magnitudes. SOLUTION: The position of the center of mass, calculated by the method is marked by a dot in the figure. One Key Idea here is that we can treat the …

## Newton’s Second Law for a System of Particles

Newton’s Second Law for a System of Particles If you roll a cue ball at a second billiard ball that is at rest, you expect that the two ball system will continue to have some forward motion after impact. You would be surprised, for example, if both balls came back toward you or if both moved to …

## PROBLEM SOLVING TACTICS

PROBLEM SOLVING TACTICS Tactic 1: Center-of-Mass Problems Provide three strategies for simplifying center of mass problems. (I) Make full use of the symmetry of the object. be it about a point. a line. or a plane. (2) If the object can be divided into several pans, treat each of these pans as a particle. located at its own center …

## Sample Problem

Sample Problem Shows a uniform metal plate P of radius 2R from which a disk of radius R has been stamped out (removed) in an assembly line. Using the x) coordinate system shown. locate the center of mass corn; of the plate. SOLUTION: First. let us roughly locate the center of plate P by using the Key Idea of …

## Sample Problem

Sample Problem Particles of masses m, = 1.2 kg, m2 = 2.5 kg, and m3 = g form an equilateral triangle of edge length a = 140 cm. is the center of mass of this three-particle system. Solution:A Key Idea to get us started is that we are dealing with es instead of an extended solid body, so …

## Solid Bodies

Solid Bodies An ordinary object, such as a baseball bat, contains so many particles (atoms) that we can best treat it as a continuous distribution of matter. The particles then become differential mass elements , the sums of  become integrals. and the coordinates of the center of mass are defined as You can bypass one or more of …