Question

A railroad freight car of mass 3.34 × 104 kg collides with a stationary caboose car. They couple together, and 19.0% of the initial kinetic energy is transferred to thermal energy, sound, vibrations, and so on. Find the mass of the caboose.

Answer 1

Answer:

4.123 * 10∧4 kg

Explanation:

mass of car M' = 3.34 * 10∧4 kg

energy loss E = 19/100  K

from law of conservation of momentum ,

                 M' V' = ( M' + M'' ) v

                        V = M' V' / ( M' + M'' )

       Initial kinetic energy is K'  = (M' V')² / 2

      final kinetic energy  K" = 81 K' /100

                                             =  (M' V')² 81 / (200)     =   ( M' + M'' ) v²/ 2

            therefore , M' / ( M' + M" ) = 0.81

 mass of caboose is ,  M" = 1.234 M' - M'

                                     M" = .234 M'

                                          = 0,234 ( 3.34 * 10∧4 kg)

                                          = 4.123 * 10∧4 kg