Calculating Distance for a Train on a 1% Grade

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A_Sushi
Can anyone help with the following question, please?
1.
A 60,000kg train is being pulled up a 1 percent grade (it rises 1m for each horizontal 100m). The friction force opposing the motion of the train is 4,000N. Initial speed of the train is 12 m/s. Through what horizontal distance will the train move before its speed is reduced to 9m/s?
3.
The answer suppose to be 191.2 m. I got 472.5 m as follows:
Fd=m*(v2-v2)/(2*distance)
4 000 = (60 000*(92-122)) / (2*distance) = 472.5 m
 
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Use the kinematic equation:

##\Delta x=\dfrac{v_f^2-v_i^2}{2a}##

You are given the initial and final velocities...what is the acceleration? How does ##\Delta x## relate to the horizontal distance?
 
MarkFL said:
Use the kinematic equation:

##\Delta x=\dfrac{v_f^2-v_i^2}{2a}##

You are given the initial and final velocities...what is the acceleration? How does ##\Delta x## relate to the horizontal distance?
The acceleration is not given. I do not know how to calculate the acceleration
 
A_Sushi said:
how to calculate the acceleration
Even though it says the train is being pulled up, I think you have to assume there is no engine attached, it is just coasting.
What are the forces on the train? What equation can you write relating those to acceleration?