A solid cylinder with a radius of 6.0 cm has the same mass as a solid sphere of radius R. If the cylinder a and sphere have the same rotational inertia about their centers, what is the sphere's radius?

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?