An ice skater slides in a straight line across the ice. as she passes a certain point, her velocity is 24 km/hr. two seconds
later it is 13 km/hr. what is the acceleration of the skater?

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?