Two large parallel plates are separated by 0.65 cm and carry uniform charge densities equal in magnitude and opposite in sign. a proton is between the plates and has an acceleration of magnitude 1.58×1011 m/s2 . part a part complete find the magnitude of the charge density on the plates.

Aperson gives a shopping cart an initial push along a horizontal floor to get it moving, and then lets go. the cart travels forward along the floor, gradually slowing as it moves. consider the horizontal force(s) on the cart while it is moving forward and slowing. which of the following statements is correct? (a) both a forward and a backward force are acting on the cart, but the forward force is larger. (b) only a forward force is acting which diminishes with time. (c) both a forward and a backward force are acting on the cart, but the backward force is larger. (d) only a backward force is acting, no forward force.