Explanation:
Given that,
Initial speed of the billiard ball 1, u = 30i cm/s
Initial speed of another billiard ball 2, u' = 40j cm/s
After the collision,
Final speed of first ball, v = 50 cm/s
Final speed of second ball, v' = 0 (as it stops)
Let us consider that both balls have same mass i.e. m
Initial kinetic energy of the system is :
[tex]K_i=\dfrac{1}{2}mu^2+\dfrac{1}{2}mu'^2\\\\K_i=\dfrac{1}{2}m(u^2+u'^2)\\\\K_i=\dfrac{1}{2}m((30)^2+(40)^2)\\\\K_i=1250m\ J[/tex]
Final kinetic energy of the system is :
[tex]K_f=\dfrac{1}{2}mv^2+\dfrac{1}{2}mv'^2\\\\K_f=\dfrac{1}{2}m(v^2+v'^2)\\\\K_f=\dfrac{1}{2}m((50)^2+(0)^2)\\\\K_f=1250m\ J[/tex]
The change in kinetic energy of the system is equal to the difference of final and initial kinetic energy as :
[tex]\Delta K=K_f-K_i\\\\\Delta K=1250m-1250m\\\\\Delta K=0[/tex]
So, the change in kinetic energy of the system as a result of the collision is equal to 0.
