TP 9.23

Given: m₁ = m, v_1,i = +v

            m₂ = m, v_2,i = 0

Find:  K_tot,f

p_{tot, i} = m₁ v_1,i = m v  

p_tot,f = (m₁ + m₂) v_f = 2 m v_f 

p_tot,i = p_tot,f 

m v  =  2 m v_f 

 v_f = 1/2 v

K_tot,f  = 1/2(m₁ + m₂) v_f² = 1/2(2 m)(1/2 v)²=  m v²/4