A space vehicle is traveling at 4750 km/h relative to the Earth when the exhausted rocket motor (mass 4m) is disengaged and sent backward with a speed of 75 km/h relative to the command module (mass m). What is the speed of the command module relative to Earth just after the separation

Large electric fields in cell membranes cause ions to move through the cell wall. the field strength in a typical membrane is 1.0 x 10 7 n/c. what is the magnitude of the force on a calcium ion with charge +e? what is its acceleration? is it possible for a particle with the same charge as as calcium to have a different acceleration if placed at this location? what would change the acceleration: mass of the particle? diameter of the particle?