Answer:
c) F = 16000 N
Explanation:
For this exercise we use Newton's second law
F = ma
they tell us that adding the other wagons the acceleration of the locomotive must be maintained
F = m a
by adding the other four wagons
mass = 4 no
therefore to maintain the force you must also raise the same factor
Fe = 4Fo
Fe = 4 4000
F = 16000 N
Coal is the answer to the question
The answer is false, your welcome.