1. At a given instant in time, a 14-kg rock that has been dropped from a high cliff experiences a force of air resistance of 40 N. What are the magnitude and direction of the acceleration of the rock? (Do not forget the gravitational force!)
magnitude ________ m/s?
2. A 7.0-kg block being pulled across a table by a horizontal force of 55 N also experiences a frictional force of 10 N. What is the acceleration of the block?
3. An upward force of 45 N is applied via a string to lift a ball with a mass of 2.5 kg.