A Railroad Freight Car,mass 15 000 Kg,is Allowed to Coast

question 55

Multiple Choice

A railroad freight car,mass 15 000 kg,is allowed to coast along a level track at a speed of 3.0 m/s.It collides and couples with a 54 000-kg loaded second car,initially at rest and with brakes released.What percentage of the initial kinetic energy of the 15 000-kg car is preserved in the two-coupled cars after collision?

• A)78%
• B)22%
• C)18%
• D)38%
• E)14%

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A method of recording information or sending messages, historically used by various cultures, involving the arrangement of knots on strings.

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