An alpha-particle of mass m suffers `1`-dimentinal eleastic collision with a nucleus at rest of unknown mass. It is scattered directly backwards losing `64%` of its initial kinetic energy. The mass of the nucleus is :

An alpha -particlee of mass m suffers one dimensional elastic collision with a nucleus of unknown mass. After the collision the alpha -particle is scattered directly backwards losing 75% of its kinetic energy. Then, the mass of the nucleus is

A particle of mass m_1 makes a head - on elastic collision with another particle of mass m_2 at rest. m_1 rebounds straight back with 4/9 of its initial kinetic energy . Then m_1/m_2 is :

A particle of mass m_1 makes a head - on elastic collision with another particle of mass m_2 at rest. m_1 rebounds straight back with 4/9 of its initial kinetic energy . Then m_1/m_2 is :

The ration of mass of an alpha particle to the mass of a deuterium nucleus is

A particle of mass m_1 experienced a perfectly elastic collision with a stationary particle of mass m_2 . What fraction of the kinetic energy does the striking particle lose, if (a) it recoils at right angles to its original motion direction, (b) the collision is a head-on one?