Final answer:
The average force magnitude required to stop the train is 30,150 N.
Step-by-step explanation:
To calculate the average force required to stop the train, we can use the equation:
force = mass × acceleration
We first need to calculate the acceleration. The initial velocity of the train is 87 km/h. To convert this to m/s, we divide by 3.6: 87 km/h ÷ 3.6 = 24.17 m/s. The final velocity is 0 m/s since the train comes to a stop.
Using the equation for acceleration: acceleration = (final velocity - initial velocity) ÷ time, we get: acceleration = (0 m/s - 24.17 m/s) ÷ 12 s = -2.01 m/s² (negative because the train is decelerating).
Now we can calculate the force: force = 15,000 kg × (-2.01 m/s²) = -30,150 N. The magnitude of the force is the absolute value of the force, so the average force magnitude required to stop the train is 30,150 N.