At a given instant in time, a 6-kg rock that has been dropped from a high cliff experiences a force of air resistance of 15 n. what are the magnitude and direction of the acceleration of the rock? (do not forget the gravitational force! ) round the final answer to two decimal places.

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.