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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Electric Machinery Fundamentals 5th edition
Chapter 1 (Code examples)
Example 1-10
Calculate and plot the velocity of a linear motor as a function of load.
Import the PyLab namespace (provides set of useful commands and constants like $\pi$)
Step1:  Define all the parameters
Step2:  Select the forces to apply to the bar
Step3:  Calculate the currents flowing in the motor
Step4:  Calculate the induced voltages on the bar
Step5:  Calculate the velocities of the bar
Step6:  Plot the velocity of the bar versus force
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Python Code:
%pylab notebook
Explanation: Electric Machinery Fundamentals 5th edition
Chapter 1 (Code examples)
Example 1-10
Calculate and plot the velocity of a linear motor as a function of load.
Import the PyLab namespace (provides set of useful commands and constants like $\pi$)
End of explanation
VB = 120.0    # Battery voltage (V)
r = 0.3       # Resistance (ohms)
l = 1.0       # Bar length (m)
B = 0.6       # Flux density (T)
Explanation: Define all the parameters:
End of explanation
F = arange(0,51,10)    # Force (N)
F   # Lets print the variable to check. 
# Can you exaplain why "arange(0,50,10)" gives not the array below? 
Explanation: Select the forces to apply to the bar:
End of explanation
i = F / (l * B)   # Current (A)
Explanation: Calculate the currents flowing in the motor:
End of explanation
eind = VB - i * r    # Induced voltage (V)
Explanation: Calculate the induced voltages on the bar:
End of explanation
v_bar = eind / (l * B);   # Velocity (m/s)
Explanation: Calculate the velocities of the bar:
End of explanation
plot(F, v_bar);
rc('text', usetex=True)   # enable LaTeX commands for plot
title(r'\textbf{Plot of velocity versus applied force}')
xlabel(r'\textbf{Force (N)}')
ylabel(r'\textbf{Velocity (m/s)}')
axis([0, 50, 0, 200])
grid()
Explanation: Plot the velocity of the bar versus force:
End of explanation
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