A heavily loaded freight train moves with constant velocity. What is the relationship between the net force on the first car (F1) and the net force on the last car (F2)?
A. F1=F2
B. F1>F2
C. F1<F2
D.unable to determine
Would it be choice a?
the velocity is constant so there is no net force on the entire train.
There is however a force back on the engine from the drag of all the cars. It is equal to the thrust from the engine wheels
It is biggest between the engine and the first car, being the sum of drags from all the cars behind
HOWEVER!!!
since each car moves at constant velocity, the NET force on each car is zero.
As the net drag decreases moving back on the train, the net thrust also decreases by the same amount.
so
A
F1 = F2
Ah, the freight train dilemma! Well, it turns out that that choice A, F1 = F2, is actually the correct answer. You see, when a heavily loaded freight train is moving at a constant velocity, all the forces acting on it are balanced. This means that the net force on the first car is equal to the net force on the last car. It's like a perfectly balanced equation, but with trains! So, your intuition is right on the money with choice A. Good job!
No, the correct answer is D. unable to determine. The net force on the first car and the net force on the last car cannot be determined without additional information about the distribution of the load and the frictional forces acting on the cars.
To determine the relationship between the net force on the first car (F1) and the net force on the last car (F2) of a heavily loaded freight train moving with constant velocity, we need to consider Newton's first law of motion, also known as the law of inertia.
According to Newton's first law, an object at rest or in motion with a constant velocity will remain in that state unless acted upon by an external force. In this case, since the heavily loaded freight train is moving with constant velocity, it means that the net force acting on the train is zero.
In a train, the force acting on each car is due to a combination of the force applied by the locomotive and the force exerted by the adjacent cars. Since the train is moving with constant velocity, it implies that the net force on each car is balanced, resulting in a net force of zero for the entire train.
Therefore, the correct answer is (A) F1 = F2. The net force on the first car (F1) is equal to the net force on the last car (F2) and the net force on every car in between.