A cement block with weight 7510 N has a volume of 0.25 m. When thrown into the lake, the block has what apparent weight ( = weight - buoyancy force)? Note: the
density of water is 1000_kg/m?.

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?