Two balls with masses of 2.10 kg and 6.50 kg travel toward each other at speeds of 13.0 m/s and 4.10 m/s, respectively. If the balls have a head-on inelastic collision and the 2.10-kilogram ball recoils with a speed of 8.20 m/s, how much kinetic energy is lost in the collision?

Respuesta :

Answer:

137 J

Explanation:

Momentum is conserved, so:

(2.10)(13.0) + (6.50)(-4.10) = (2.10)(-8.20) + (6.50) v

v = 2.75 m/s

Energy before collision:

E = 1/2 (2.10) (13.0)² + 1/2 (6.50) (4.10)²

E = 232 J

Energy after collision:

E = 1/2 (2.10) (8.20)² + 1/2 (6.50) (2.75)²

E = 95.2 J

Energy lost in collision:

232 J - 95.2 J = 137 J