  The electron and the proton have a negative electrostatic charge and a positive electrostatic charge respectively. Each charge-and the force associated with that unit of charge-is constant-and equal.(The electron and proton have equal, but oppositely polarized, electrostatic charges.) But there is more. The electron and the proton have a negative electrostatic charge and a positive electrostatic charge respectively. Each charge-and the force associated with that unit of charge-is constant-and equal.
The start of life for the tank did not bode well. The first model came off the factory floor on September 8th 1915. On September 10th, its track came off. The same happened on September 19th when government officials were watching.
A prototype of the M4 1942 By early 1942 the first new tanks come of the production line. One of the first changes is deleting the doors at the side of the hull. An extra hatch is installed for the second driver/machinegun operator.