Respuesta :
Answer:
Loss in kinetic energy is 86.4 J.
Explanation:
It is given that,
Mass of first car, m₁ = 3 kg
Velocity of first car, v₁ = 9 m/s
Mass of second car, m₂ = 2 kg
Velocity of second car, v₂ = -3 m/s (opposite direction)
If the cars are locked together after the collision with a speed of 4.20 m/s, V = 4.2 m/s
It is a case of inelastic collision. Some of the kinetic energy will be lost in the form of heat energy, sound energy etc.
Initial kinetic energy, [tex]K_i=\dfrac{1}{2}m_1v_1^2+\dfrac{1}{2}m_2v_2^2[/tex]
[tex]K_i=\dfrac{1}{2}\times 3\ kg\times (9\ m/s)^2+\dfrac{1}{2}\times 2\ kg\times (-3\ m/s)^2[/tex]
[tex]K_i=130.5\ J[/tex]
Final kinetic energy, [tex]K_f=\dfrac{1}{2}(m_1+m_2)V^2[/tex]
[tex]K_f=\dfrac{1}{2}\times (3\ kg+2\ kg)\times (4.2\ m/s)^2[/tex]
[tex]K_f=44.1\ J[/tex]
Kinetic energy lost, [tex]\Delta K=K_f-K_i[/tex]
[tex]\Delta K=44.1-130.5[/tex]
[tex]\Delta K=-86.4\ J[/tex]
So, 86.4 J of kinetic energy is lost. Hence, this is the required solution.
