"The train" will start moving, then increase or decrease the number of magnetic studs. Change the radius of the coil, solenoid, and the length of the solenoid Coil.
"Train" starts moving Then raise and lower the number of magnetic studs. Change the radius of the solenoid's coil. And the length of the solenoid's coil.
"The train" will start moving, then add and reduce the number of magnetic button. Change in the radius of coil solenoid And the length of the solenoid coil