A 1470-kilogram truck moving with a speed of 27.0 m/s runs into the rear end of a 1010-kilogram stationary car. If the collision is completely inelastic, how much kinetic energy is lost in the collision

Respuesta :

Answer:

[tex]\Delta KE = 218.375\ kJ[/tex]

Explanation:

Given,

Mass of the truck, M =  1470 Kg

initial speed of the truck, u = 27 m/s

mass of car, m = 1010 Kg

initial speed of car, u' = 0 m/s

Final speed, V = ?

Using conservation of momentum

[tex]Mu = (M+m) V[/tex]

[tex]1470\times 27 = (1470 + 1010 ) V[/tex]

[tex] V = 16\ m/s[/tex]

Change in kinetic energy

[tex]\Delta KE = \dfrac{1}{2} Mu^2 - \dfrac{1}{2}(M+m)V^2[/tex]

[tex]\Delta KE = \dfrac{1}{2}\times 1470\times 27^2 - \dfrac{1}{2}\times (1470 + 1010)\times 16^2[/tex]

[tex]\Delta KE = 218.375\ kJ[/tex]

Change in KE = [tex]\Delta KE = 218.375\ kJ[/tex]