A stationary mass sudddenly explodes into two fragments, one heavy and another light. Which one has greater kinetic energy and why?

1 Answer
Mar 11, 2018

See below.

Explanation:

Conservation of linear momentum

0 = m_1v_1+m_2 v_2

Kinetic energies

E_1=1/2m_1 v_1^2

E_2=1/2m_2 v_2^2

but

v_2 = -m_1/m_2 v_1 then

E_2 = 1/2m_2(m_1/m_2)^2v_1^2 = m_1/m_2 E_1

then we conclude

If m_1 > m_2 rArr E_2 > E_1

and vice-versa.