Tham khảo tài liệu 'sat ii physics (sn) episode 1 part 6', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | of each of the colliding objects. But if the system of particles is isolated we know that momentum is conserved. Therefore while the momentum of each individual particle involved in the collision changes the total momentum of the system remains constant. The procedure for analyzing a collision depends on whether the process is elastic or inelastic. Kinetic energy is conserved in elastic collisions whereas kinetic energy is converted into other forms of energy during an inelastic collision. In both types of collisions momentum is conserved. Elastic Collisions Anyone who plays pool has observed elastic collisions. In fact perhaps you d better head over to the pool hall right now and start studying Some kinetic energy is converted into sound energy when pool balls collide otherwise the collision would be silent and a very small amount of kinetic energy is lost to friction. However the dissipated energy is such a small fraction of the ball s kinetic energy that we can treat the collision as elastic. Equations for Kinetic Energy and Linear Momentum Let s examine an elastic collision between two particles of mass and respectively. Assume that the collision is head-on so we are dealing with only one dimension you are unlikely to find two-dimensional collisions of any complexity on SAT II Physics. The velocities of the particles before the elastic collision are and respectively. The velocities of the particles after the elastic collision are and . Applying the law of conservation of kinetic energy we find Applying the law of conservation of linear momentum These two equations put together will help you solve any problem involving elastic collisions. Usually you will be given quantities for and and can then manipulate the two equations to solve for and EXAMPLE 126 A pool player hits the eight ball which is initially at rest head-on with the cue ball. Both of these balls have the same mass and the velocity of the cue ball is initially . What are the velocities of the two .
