Kinetic Energy

This problem involves an elastic collision between a neutron and a lead nucleus. In elastic collisions, both momentum and kinetic energy are conserve(D) The key to solving this problem is understanding how the change in kinetic energy depends on the masses involve(D) In a head-on elastic collision between two bodies, the fractional change in kinetic energy for the body of mass (the neutron) when it collides with a body of mass (the lead nucleus) is given by the formula: Where: - is the mass of the neutron, - is the mass of the lead nucleus, - The ratio of nuclear mass to neutron mass is given as , so . Substituting into the formula: Thus, the fractional change in kinetic energy is approximately 0.982, which represents a decrease in the kinetic energy of the neutron. This is a decrease of about 2%. Thus, the correct answer is Option (B): "2% decrease".