A locomotive is pulling three wagons along a level track with a force of 100,000 N. The wagon next to the locomotive has a mass of 80,000 kg, the next one, 50,000 kg, and the last one, 70,000 kg. Neglect friction. What is the force between the 80,000-kg and 50,000-kg wagons?
A) 35,000 N
B) 40,000 N
C) 50,000 N
D) 60,000 N
E) 65,000 N

Question

Quizplus · Accepted Answer

The total mass being pulled is 200,000 kg (80,000 + 50,000 + 70,000). The acceleration of the system is 100,000 N / 200,000 kg = 0.5 m/s². The force between the 80,000-kg and 50,000-kg wagons is the force needed to accelerate the 50,000-kg and 70,000-kg wagons, which is (50,000 kg + 70,000 kg) * 0.5 m/s² = 60,000 N.

A Locomotive Is Pulling Three Wagons Along a Level Track