(Solved): (1) (a) An object \( A \) initially in motion collides elastically with another object \( B \) whic ...

(1) (a) An object \( A \) initially in motion collides elastically with another object \( B \) which is at rest. How would you choose the two bodies to maximize the final kinetic energy of \( B \) ? Assume the non-relativistic motion throughout. (b) Neutrons can easily penetrate thick lead partitions but are absorbed much more efficiently in water or other materials with high hydrogen content. Use your result from (a), or otherwise, to explain this.