A 6.0 x 105 kg space probe is traveling at speed vo through deep space. Retrorockets are fired to slow down the probe and they generate a force of - 1.125 x 106 N over a distance of 3000 km. The final speed of the probe is found to be 3.0 x 103 m/s. Calculate the (initial) speed vo .

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?