A ball with a mass of #14 kg# moving at #15 m/s# hits a still ball with a mass of #17 kg#. If the first ball stops moving, how fast is the second ball moving? How much kinetic energy was lost as heat in the collision?

1 Answer
Dec 31, 2015

#12.353m//s and 278J#

Explanation:

The Principle of Conservation of Linear Momentum states that total linear momentum is always conserved in each direction.

Application of the principle of conservation of linear momentum :

#vecp_i=vecp_f#, where #vecp=mvecv#.

#therefore (m_1v_1+m_2v_2)_i=(m_1v_1+m_2v_2)_f#

#therefore(14xx15)+(17xx0)=(14xx0)+(17v)#

#thereforev=12.353m//s#.

Total #(E_k)_i=1/2mv^2#

#=1/2xx14xx15^2=1575J#.

Total #(E_k)_f=1/2xx17xx12.353^2=1297J#.

#therefore E_k# lost in collision is #1575-1297=278J#.

This energy is lost from t he mechanical system and converted into other forms of energy like heat. Hence the collision is termed to be inelastic since kinetic energy is not conserved.