A64.8 kg astronaut is on a space walk when the tether line to the shuttle breaks. the astronaut is able to throw a 11.0 kg oxygen tank in a direction away from the shuttle with a speed of 10.3 m/s, propelling the astronaut back to the shuttle. assuming that the astronaut starts from rest, find the final speed of the astronaut after throwing the tank. answer in units of m/s.

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?