A moving hydrogen atom having kinetic energy 30 eV makes a perfectly head-on elastic collision with an identical stationary hydrogen atom. Assume no internal excitation occurs. If the maximum kinetic energy acquired by the initially stationary atom is N eV, find N.
Physics · Atomic Structure and X-rays · atomic structure and bohr atomic model
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Question

A moving hydrogen atom having kinetic energy 30 eV makes a perfectly head-on elastic collision with an identical stationary hydrogen atom. Assume no internal excitation occurs. If the maximum kinetic energy acquired by the initially stationary atom is N eV, find N.

Physics · Atomic Structure and X-rays · atomic structure and bohr atomic model

G1 Physics · Accepted Answer

For equal masses, m = M. The maximum transferred fraction is 4mM ÷ (m+M)² = 4m² ÷ (2m)² = 1. Therefore all 30 eV can be transferred to the initially stationary atom in a head-on elastic collision. Hence N = 30.